It was in Jakarta, on the last leg of Chelsea's tour of south-east Asia in July, that the conversation turned to Juan Mata and, more specifically, what it was that Jose Mourinho expected of the man who had been the outstanding player under Rafa Benitez.

First Mourinho mentioned the fact, often repeated since, that Mata had won both player of the year trophies the previous season – one voted for by the fans, the other by the players. In fact, Mata has won the players' award for the last two years and this seemed to have made an impression on Mourinho, who acknowledged the status of the Spaniard.

"That means a lot," Mourinho said at the time. "People love him, but also the fellow players love the work he did for the team. Of course, he fits in my plans. I know him quite well. I have my idea about him. I have my idea about where and how he produces better, and where he has more difficulty. But we are here to try and keep him performing when he is, and try and help him to perform better in the situations where he finds it a bit more difficult."

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Even at the time it was a remark that grabbed the attention. There had been rumours Mata was not the kind of player Mourinho would ordinarily have signed and here was the new Chelsea manager implying exactly that. Mata, who had won the Champions League and the Europa League in his two seasons at Chelsea, was important. But he could be improved.

Looking back six months on, as the Chelsea hierarchy determine their likely response in the event of a £40m-plus bid for Mata from Manchester United, it is clear that there were doubts from the start. Just how quickly Mata has fallen from grace at Chelsea has surprised even those at the club, although they agree that his current role as non-playing substitute is untenable in the long-term.

It is for that reason they are considering what to do in the event of a United offer. From the perspective of the demands of Uefa Financial Fair Play, and the prospect of obtaining premium value, selling Mata makes sense. But the club also recognise that there are few assets like the 25-year-old and it only takes one injury for him to be first choice again.

Chelsea acknowledge that difficult choices have to be made, that not every player is suited to a life on the bench to be called upon when needed, that sometimes a bold decision can have an energising effect on a squad.

At Chelsea the feeling is that Mata's late arrival to join up with the squad in pre-season, having played at the Confederations Cup, cost him dear. He was not the only one who joined up after the Asia tour for the games in America in early August. So too did Oscar, the man who has taken his place, as well as the likes of Fernando Torres, David Luiz and Cesar Azpilicueta.

But with Mourinho already doubtful about Mata it meant that at a crucial time, when the new manager was putting together his team, imposing a style and expectations, Mata was absent. He started in the second game of the season against Aston Villa but did not play a full 90 minutes until the Capital One Cup third-round tie against Swindon on 24 September. Since then he has played a full 90 minutes just twice.

Inside the club, the indication is that Mourinho told Mata over the opening months of the season that he should be patient and his run in the team would come. But that has not happened and both parties are aware that to continue saying the same would be to insult the player's intelligence.

If Mata is to leave, the club and Mourinho want it to be on the best of terms. There remains a great deal of respect for a superb professional who has more than delivered on the £23m fee paid to Valencia for him in August 2011. Chelsea had been offered Mata the previous two summers but only turned their attention to him when their efforts to sign Luka Modric and Neymar came to nought.

As with all major decisions that encompass so many factors there is a possibility that it could cost Chelsea in the future. Nevertheless, the consensus is that the current situation, with such a popular individual on the bench, only creates pressure for both manager and player. Mata's angry reaction to being substituted on New Year's Day raised the tension.

Why does Mourinho not play him? He has been frank about the responsibilities of the attacking three behind the striker to apply pressure. As he said after Sunday's victory over Manchester United, his is a team "that runs a lot". "We press very high on the pitch. My attacking players have big distances to run between the initial pressure and the way they compact with the defensive players." That is not Mata's natural game.

Mourinho has eulogised the work rate of Oscar who, if the Chelsea manager was asked to name his most influential attacking player now, would be the only individual with a chance of pipping Eden Hazard. Oscar and Hazard have been the most willing participants in the Mourinho revolution.

There is a possibility, those at the club acknowledge, that Mourinho's system could one day be refined to include Mata. But given the various pressures upon them, of FFP and the tension of an unhappy player, waiting for things to change is not an option. They have to make a decision on Mata's future now and, with the potential to earn their biggest transfer fee, there is a good chance he will leave.

Shape Created with Sketch. Manchester United - January transfer targets Show all 21 left Created with Sketch. right Created with Sketch. Shape Created with Sketch. Manchester United - January transfer targets 1/21 Dante Bayern Munich defender Dante would be interested in a move to the Premier League according to his agent - and United have been monitoring him. His current club could yet convince the defender to stay however. GETTY IMAGES 2/21 Alberto Herrera United tried to sign the Athletic Bilbao midfielder in the summer but his botched signing rather summed up their ineffective dealings in the transfer market. With a £30m release clause, he remains an available, if perhaps slightly pricey, option in January. Getty Images 3/21 Mario Mandzukic An old-fashioned target man, Mandzukic has been linked with a move to United recently after Bayern signed Robert Lewandowski. However, Lewandowski won't arrive until the summer - meaning United might have to wait. Reuters 4/21 Will Hughes Will Hughes has emerged as a transfer target for Manchester United boss David Moyes after a series of superb performances have catapulted Derby County into the upper reaches of the Championship. 5/21 Guarin There is no doubt that midfield is the area most in need of reinforcements for David Moyes and another man linked with an Old Trafford switch is Colombian international Guarin. Valued at around £15m, the Inter Milan man's versatility would undeniably improve things for the Red Devils. Getty Images 6/21 Bilal Basacikoglu Bilal who, you might ask, but the young Turkish winger is an emerging star at Dutch side Heerenveen and a player to catch the eye of David Moyes. Aged just 18, he may be a player more for the future than to immediately turn United's fortunes around. 7/21 Steven Defour For many years the Belgian was linked with a move to Old Trafford and having been a target of Moyes' at Everton, the midfielder could very well be the man brought in to improve things for United. Played for Porto recently against Atletico Madrid in a match watched by Moyes - did he catch the Scotsman's eye? Getty Images 8/21 Koke Reportedly one of United's main January targets, although the Atletico Madrid man is said to be very happy in the Spanish capital, particularly given his team's success this season. Might take some persuading to join Moyes' stuttering side. Getty Images 9/21 Ilkay Gundogan Undeterred by the modest success of their last Dortmund purchase, United could also be after midfielder Gundogan. Wouldn't be cheap but certainly an improvement on their current crop of players. Dortmund are understood to be keen to tie him to a new contract. Getty Images 10/21 Sami Khedira Another strongly linked with a Manchester move, the German international's recent serious knee injury makes a January switch unlikely but he could be brought in from Real Madrid further down the line. Getty Images 11/21 Ross Barkley Manchester United bought the last exciting teenage prospect to come through Everton's ranks so understandably they have been linked with the precocious Barkley. Knows Moyes from his Everton days, but will he join the Scot in making the switch from Blue to Red? Everton have already stated they will not sell in January. Getty Images 12/21 Fabio Coentrao After nearly signing on deadline day last summer, there's every chance that Moyes could return for Real Madrid's second choice left-back should he fail to lure another top name. Not really the priority though considering the good form of Patrice Evra. GETTY IMAGES 13/21 Eliaquim Mangala United could do with strengthening at the back and French defender Mangala is reportedly another to have caught Moyes' eye. However with Porto wanting all of his £40m release clause, he seems a rather pricey option. Getty Images 14/21 Diego Costa Rooney and Van Persie have spent too much time this season on the treatment table - so more options in attack would be helpful. Who better then than a failed target of eternal rivals Liverpool and a man whose goals have fired Atletico Madrid to the top of La Liga? Highly unlikely Costa would wish to leave in January - and even less likely Atletico would let him. GETTY IMAGES 15/21 Blaise Matuidi Another midfielder strongly linked with an Old Trafford switch, the PSG man could be available for as little as £7m which would represent great value for money. Not the sort of signing to instil renewed confidence at Old Trafford - but perhaps one of the more likely arrivals. Getty Images 16/21 Andrea Ranocchia Another man being mooted as a defensive recruit for Moyes, the towering Italian has fallen out of favour at the San Siro and would surely jump at a move to Manchester United. 17/21 Everton Ribeiro The 24-year-old Cruzeiro man believes he could be the solution to United's midfield woes after being linked with a move there saying: 'I would fit in any part of the midfield. I would do well as a playmaker to support the attack.' It remains to be seen whether he'll get the chance to prove it with a January move. 18/21 Miralem Pjanic The Bosnian midfielder has excelled at Roma this season and would certainly be a good signing for United. Previously linked with moves to Arsenal and Spurs, a move to Manchester would mean no Pjanic on the streets of London. Roma have confirmed they have received offers for the Pjanic. <b>Miralem Pjanic</b> The Bosnian midfielder has excelled at Roma this season and would certainly be a good signing for United. Previously linked with moves to Arsenal and Spurs, a move to Manchester would mean no Pjanic on the streets of London. 19/21 Kevin Strootman Another Roma star thought to be wanted by United, the Dutch midfielder is however highly valued by Roma chief Rudi Garcia which may prove an obstacle to any move. 20/21 Toni Kroos The Bayern Munich midfielder is stalling on a new contract, raising hope he could be prised away. However, he's been integral to the multi-trophy winning side and it seems highly unlikely the German champions will let him go. GETTY IMAGES 21/21 Alex Teixeira If their pursuit of Strootman falls through, another man reportedly being lined up is Shakhtar midfielder Teixeira. The 23-year-old impressed against United in his side's recent visit to Old Trafford. 1/21 Dante Bayern Munich defender Dante would be interested in a move to the Premier League according to his agent - and United have been monitoring him. His current club could yet convince the defender to stay however. GETTY IMAGES 2/21 Alberto Herrera United tried to sign the Athletic Bilbao midfielder in the summer but his botched signing rather summed up their ineffective dealings in the transfer market. With a £30m release clause, he remains an available, if perhaps slightly pricey, option in January. Getty Images 3/21 Mario Mandzukic An old-fashioned target man, Mandzukic has been linked with a move to United recently after Bayern signed Robert Lewandowski. However, Lewandowski won't arrive until the summer - meaning United might have to wait. Reuters 4/21 Will Hughes Will Hughes has emerged as a transfer target for Manchester United boss David Moyes after a series of superb performances have catapulted Derby County into the upper reaches of the Championship. 5/21 Guarin There is no doubt that midfield is the area most in need of reinforcements for David Moyes and another man linked with an Old Trafford switch is Colombian international Guarin. Valued at around £15m, the Inter Milan man's versatility would undeniably improve things for the Red Devils. Getty Images 6/21 Bilal Basacikoglu Bilal who, you might ask, but the young Turkish winger is an emerging star at Dutch side Heerenveen and a player to catch the eye of David Moyes. Aged just 18, he may be a player more for the future than to immediately turn United's fortunes around. 7/21 Steven Defour For many years the Belgian was linked with a move to Old Trafford and having been a target of Moyes' at Everton, the midfielder could very well be the man brought in to improve things for United. Played for Porto recently against Atletico Madrid in a match watched by Moyes - did he catch the Scotsman's eye? Getty Images 8/21 Koke Reportedly one of United's main January targets, although the Atletico Madrid man is said to be very happy in the Spanish capital, particularly given his team's success this season. Might take some persuading to join Moyes' stuttering side. Getty Images 9/21 Ilkay Gundogan Undeterred by the modest success of their last Dortmund purchase, United could also be after midfielder Gundogan. Wouldn't be cheap but certainly an improvement on their current crop of players. Dortmund are understood to be keen to tie him to a new contract. Getty Images 10/21 Sami Khedira Another strongly linked with a Manchester move, the German international's recent serious knee injury makes a January switch unlikely but he could be brought in from Real Madrid further down the line. Getty Images 11/21 Ross Barkley Manchester United bought the last exciting teenage prospect to come through Everton's ranks so understandably they have been linked with the precocious Barkley. Knows Moyes from his Everton days, but will he join the Scot in making the switch from Blue to Red? Everton have already stated they will not sell in January. Getty Images 12/21 Fabio Coentrao After nearly signing on deadline day last summer, there's every chance that Moyes could return for Real Madrid's second choice left-back should he fail to lure another top name. Not really the priority though considering the good form of Patrice Evra. GETTY IMAGES 13/21 Eliaquim Mangala United could do with strengthening at the back and French defender Mangala is reportedly another to have caught Moyes' eye. However with Porto wanting all of his £40m release clause, he seems a rather pricey option. Getty Images 14/21 Diego Costa Rooney and Van Persie have spent too much time this season on the treatment table - so more options in attack would be helpful. Who better then than a failed target of eternal rivals Liverpool and a man whose goals have fired Atletico Madrid to the top of La Liga? Highly unlikely Costa would wish to leave in January - and even less likely Atletico would let him. GETTY IMAGES 15/21 Blaise Matuidi Another midfielder strongly linked with an Old Trafford switch, the PSG man could be available for as little as £7m which would represent great value for money. Not the sort of signing to instil renewed confidence at Old Trafford - but perhaps one of the more likely arrivals. Getty Images 16/21 Andrea Ranocchia Another man being mooted as a defensive recruit for Moyes, the towering Italian has fallen out of favour at the San Siro and would surely jump at a move to Manchester United. 17/21 Everton Ribeiro The 24-year-old Cruzeiro man believes he could be the solution to United's midfield woes after being linked with a move there saying: 'I would fit in any part of the midfield. I would do well as a playmaker to support the attack.' It remains to be seen whether he'll get the chance to prove it with a January move. 18/21 Miralem Pjanic The Bosnian midfielder has excelled at Roma this season and would certainly be a good signing for United. Previously linked with moves to Arsenal and Spurs, a move to Manchester would mean no Pjanic on the streets of London. Roma have confirmed they have received offers for the Pjanic. <b>Miralem Pjanic</b> The Bosnian midfielder has excelled at Roma this season and would certainly be a good signing for United. Previously linked with moves to Arsenal and Spurs, a move to Manchester would mean no Pjanic on the streets of London. 19/21 Kevin Strootman Another Roma star thought to be wanted by United, the Dutch midfielder is however highly valued by Roma chief Rudi Garcia which may prove an obstacle to any move. 20/21 Toni Kroos The Bayern Munich midfielder is stalling on a new contract, raising hope he could be prised away. However, he's been integral to the multi-trophy winning side and it seems highly unlikely the German champions will let him go. GETTY IMAGES 21/21 Alex Teixeira If their pursuit of Strootman falls through, another man reportedly being lined up is Shakhtar midfielder Teixeira. The 23-year-old impressed against United in his side's recent visit to Old Trafford.

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