Arsene Wenger has argued that Juan Mata's upcoming move from Chelsea to Manchester United is unfair, claiming that Chelsea are happier to strengthen a team who they have already played twice in the league this season, making United tougher opponents for the rest of the Blues' title rivals.

"Yes I am [suprised] because Juan Mata is a great player, and they are selling a great player to a direct opponent," the Arsenal manager said in his press briefing ahead of the Gunners' FA Cup tie against Coventry City on Friday.

"It opens up the opportunities in this transfer market because Chelsea have already played twice against Man United and so don't play them again anymore," Wenger added. United lost 3-1 at Chelsea last weekend, while the teams drew 0-0 at Old Trafford back in August. Chelsea could still come up against United in the Champions League but Mata would be ineligible.

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"United could have sold him last week but it opens at least the dates of this transfer window. Some teams have already played twice against one opponent and some others not and I think if you want to respect the fairness for everybody - exactly the same - that should not happen."

Asked whether it was purely a tactical move, Wenger replied: "I wouldn't go as far as that, I just think you would want that everybody is at the same level. I can understand completely what Chelsea are doing, it's within the rules but maybe the rules should be adapted for fairness."

Wenger had admitted in August that he would have liked to have signed the Spanish midfielder in the summer window, but at the time spoke of English clubs "reluctance" to sell to each other.

Including Mata, here are the biggest deals yet to happen in this transfer window

Shape Created with Sketch. What are the biggest January transfers yet to happen? Show all 8 left Created with Sketch. right Created with Sketch. Shape Created with Sketch. What are the biggest January transfers yet to happen? 1/8 Tom Ince to Monaco, £10m Monaco are leading the race to sign Blackpool winger Tom Ince according to reports. The England U21 international was reportedly driven by his father, Blackpool boss Paul Ince, to a meeting with representatives of the French club in London. The Blackpool boss cancelled a press conference ahead of his side's match with Barnsley earlier in the month after refusing to answer questions about his son's future. Instead he reportedly went to meet Monaco representatives, who can speak to the player whose contract expires in six months. Getty Images 2/8 Edinson Cavani to Manchester United, £40m Should United take the plunge and sell Wayne Rooney (either to Chelsea or otherwise) they'll need a replacement to fill his impervious shoes. The England striker will be out of contract next summer and is believed to want to make a decision on his future once the season has developed. Edinson Cavani is the international strike partner of fellow Uruguayan Luis Suarez and is reportedly disillusioned by football in Ligue 1. Reports surfaced this month that Sir Alex Ferguson had rung his former player Laurent Blanc, the current PSG manager, to sound out a possible move. GETTY IMAGES 3/8 Yohan Cabaye to PSG, £21m Newcastle United are preparing themselves for a considerable offer for Yohan Cabaye from the French giants after it emerged that they are willing to part with £21m for the midfielder. PSG have held a firm interest in the 28-year-old Frenchman for over a year and were expected to rival Arsenal for his signature in the summer. The Gunners' £10m bid was rejected and the Parisian club opted to bide their time despite Cabaye missing three games in an attempt to force a move away from St. James' Park. GETTY IMAGES 4/8 Dimitar Berbatov (back) to Tottenham, £1.5m His agent has already claimed that the Bulgarian would like to leave Fulham this month despite his contract expiring at the end of the season. With £2m believed to be enough to secure skillful striker, it would be a low cost, low risk option, but questions remain over his work rate and energy levels. Whether Berbatov would quench the thirst of fans who feel another striker is integral to their top four hopes remains uncertain, but he does come with a natural talent that few in the Premier League can match – if only he produced it regularly. Getty Images 5/8 Miralem Pjanic to Manchester United, £27m Roma star Miralem Pjanic has left the door open on a possible move to reigning Premier League champions Manchester United after admitting that he is 'flattered' by their interest. The 23-year-old Bosnia and Herzegovina international is also attracting attention from French giants Paris Saint Germain. Despite a move seeming unlikely during January, Pjanic appears open to a potential switch. It's a shame he isn't moving to a club in the capital, just because we could bring out our best 'Pjanic on the streets of London' gags. GETTY IMAGES 6/8 Andriy Yarmolenko to Liverpool, £10m Should they miss out on Salah, Liverpool may switch their attention to Dynamo Kiev's Andriy Yarmolenko. The Reds have held a tentative interest in the 24-year-old after he figured prominently for the Ukraine against England in last year's World Cup qualifiers. Yarmolenko has scored eight league goals in sixteen appearances for Kiev this season, and has fourteen goals for Ukraine. Kop manager Brendan Rodgers is rumoured to prefer Salah, but the Swiss club continue to stall on any potential deal. 7/8 Ravel Morrison to Fulham, £8m West Ham want a minimum of £10m for their sought-after midfielder Ravel Morrison, according to reports. Sam Allardyce's side have already rejected a £5m bid from Fulham and reported the club to the FA for alleged tapping up of the player. Fulham boss Rene Meulensteen has now reportedly been banned from talking about any transfers as the club try to avoid any more trouble. However West Ham No. 2 Neil McDonald said: “I would imagine everybody has a price. Asked if the Hammers want to keep the England under-21 star, he added: “Why not? He’s a talented player and we need talented players." Getty Images 8/8 Ilkay Gundogan to Manchester United, £25m United’s search for midfield reinforcements has led them to Borussia Dortmund’s Ilkay Gundogan, although they could face a fight with Real Madrid to sign the Germany international. With Anderson at Fiorentina on loan, it is believed David Moyes has stepped up his interest in 23-year-old Gundogan whose contract expires in 18 months and is valued at £25m. Part of the attraction is that the midfielder is not cup-tied for the Champions League as he has been out for most of the season with a back injury, although German newspaper Bild reports that Real are also admirers. “I will soon make a decision that will be well considered. It’s still really open,” Gundogan said yesterday. Getty Images 1/8 Tom Ince to Monaco, £10m Monaco are leading the race to sign Blackpool winger Tom Ince according to reports. The England U21 international was reportedly driven by his father, Blackpool boss Paul Ince, to a meeting with representatives of the French club in London. The Blackpool boss cancelled a press conference ahead of his side's match with Barnsley earlier in the month after refusing to answer questions about his son's future. Instead he reportedly went to meet Monaco representatives, who can speak to the player whose contract expires in six months. Getty Images 2/8 Edinson Cavani to Manchester United, £40m Should United take the plunge and sell Wayne Rooney (either to Chelsea or otherwise) they'll need a replacement to fill his impervious shoes. The England striker will be out of contract next summer and is believed to want to make a decision on his future once the season has developed. Edinson Cavani is the international strike partner of fellow Uruguayan Luis Suarez and is reportedly disillusioned by football in Ligue 1. Reports surfaced this month that Sir Alex Ferguson had rung his former player Laurent Blanc, the current PSG manager, to sound out a possible move. GETTY IMAGES 3/8 Yohan Cabaye to PSG, £21m Newcastle United are preparing themselves for a considerable offer for Yohan Cabaye from the French giants after it emerged that they are willing to part with £21m for the midfielder. PSG have held a firm interest in the 28-year-old Frenchman for over a year and were expected to rival Arsenal for his signature in the summer. The Gunners' £10m bid was rejected and the Parisian club opted to bide their time despite Cabaye missing three games in an attempt to force a move away from St. James' Park. GETTY IMAGES 4/8 Dimitar Berbatov (back) to Tottenham, £1.5m His agent has already claimed that the Bulgarian would like to leave Fulham this month despite his contract expiring at the end of the season. With £2m believed to be enough to secure skillful striker, it would be a low cost, low risk option, but questions remain over his work rate and energy levels. Whether Berbatov would quench the thirst of fans who feel another striker is integral to their top four hopes remains uncertain, but he does come with a natural talent that few in the Premier League can match – if only he produced it regularly. Getty Images 5/8 Miralem Pjanic to Manchester United, £27m Roma star Miralem Pjanic has left the door open on a possible move to reigning Premier League champions Manchester United after admitting that he is 'flattered' by their interest. The 23-year-old Bosnia and Herzegovina international is also attracting attention from French giants Paris Saint Germain. Despite a move seeming unlikely during January, Pjanic appears open to a potential switch. It's a shame he isn't moving to a club in the capital, just because we could bring out our best 'Pjanic on the streets of London' gags. GETTY IMAGES 6/8 Andriy Yarmolenko to Liverpool, £10m Should they miss out on Salah, Liverpool may switch their attention to Dynamo Kiev's Andriy Yarmolenko. The Reds have held a tentative interest in the 24-year-old after he figured prominently for the Ukraine against England in last year's World Cup qualifiers. Yarmolenko has scored eight league goals in sixteen appearances for Kiev this season, and has fourteen goals for Ukraine. Kop manager Brendan Rodgers is rumoured to prefer Salah, but the Swiss club continue to stall on any potential deal. 7/8 Ravel Morrison to Fulham, £8m West Ham want a minimum of £10m for their sought-after midfielder Ravel Morrison, according to reports. Sam Allardyce's side have already rejected a £5m bid from Fulham and reported the club to the FA for alleged tapping up of the player. Fulham boss Rene Meulensteen has now reportedly been banned from talking about any transfers as the club try to avoid any more trouble. However West Ham No. 2 Neil McDonald said: “I would imagine everybody has a price. Asked if the Hammers want to keep the England under-21 star, he added: “Why not? He’s a talented player and we need talented players." Getty Images 8/8 Ilkay Gundogan to Manchester United, £25m United’s search for midfield reinforcements has led them to Borussia Dortmund’s Ilkay Gundogan, although they could face a fight with Real Madrid to sign the Germany international. With Anderson at Fiorentina on loan, it is believed David Moyes has stepped up his interest in 23-year-old Gundogan whose contract expires in 18 months and is valued at £25m. Part of the attraction is that the midfielder is not cup-tied for the Champions League as he has been out for most of the season with a back injury, although German newspaper Bild reports that Real are also admirers. “I will soon make a decision that will be well considered. It’s still really open,” Gundogan said yesterday. Getty Images

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