Sporting Lisbon are hoping to spark a bidding war for midfielder William Carvalho after dropping their asking price to £21.5million.

Chelsea, Arsenal, Manchester United and Liverpool have all been linked with a move for the 23-year-old but clubs have considered a deal too complicated and expensive to complete until now.

Sporting initially insisted last summer that potential suitors would be forced to meet the £35million release clause in his contract. All interested parties refused and once that clause expired, Sporting softened their stance and indicated they were willing to accept £30million.

Arsenal expressed an interest in signing Carvalho but at a lower level, believing the price to be inflated by the presence of a third-party ownership agreement.

Back in 2011, Carvalho’s rights were part-sold to Banco Espirito Santo, once the second largest bank in Portugal. BES are thought to have bought a 40 per cent stake in Carvalho for 400,000 euros.

With the Premier League banning the transfer of any player with third-party ownership, English clubs were put off by the complexity of the deal, especially given BES’ involvement was driving the overall cost to what was viewed as an unacceptable level.

Arsenal vs Chelsea: Ten classic matches 10 show all Arsenal vs Chelsea: Ten classic matches 1/10 Chapman's champions set the mark November 1930: Chelsea 1-5 Arsenal



To this day, the clash back in November 1930 remains Arsenal biggest victory over the Blues. David Jack was the star that day, as his hat-trick fired Herbert Chapman’s side to a convincing 5-1 victory.



Arsenal would go on to win their first championship title that season. 2/10 Arsenal out gun Blues March 1958: Arsenal 5-4 Chelsea



The Highbury showdown back in 1958 was the highest scoring derby meeting on record between these two rivals.



Another David scored a hat-trick that day, with Arsenal's Herd netting a treble. 3/10 So good March 1973: Chelsea 2-2 Arsenal



One of THE goals between these sides kick-started a memorable FA Cup encounter.



Peter Osgood's exquisite volley in the quarter-finals opened the scoring as the sides played out a 2-2 draw at Stamford Bridge.



The Gunners would go on to win the replay 2-1. 4/10 Almost invincible February 1991: Chelsea 2-1 Arsenal



Everyone remembers Arsenal 'Invincibles' from the 2003-04 season, but many forget they came close to that feat back in 1991.



George Graham's side would finish champions come May, but his Gunners only suffered one defeat that season.



Terry Dixon and Graham Stuart scored the goals as Chelsea recorded a 2-1 victory at the Bridge.



Photo by Colorsport/REX 5/10 Kanu believe it?! October 1999: Chelsea 2-3 Arsenal



Forget just the derby, this is a Premier League classic in it's own right.



Arsene Wenger's side were trailing 2-0 with 15 minutes to go, only to be blitz the Blues with a sensational hat-trick from Nwankwo Kanu after Tore-Andre Flo and Dan Petrescu had put Chelsea ahead. 6/10 First finale May 2002: Arsenal 2-0 Chelsea



Arsenal's victory in the Millennium Stadium not only secured the FA Cup, but also the bragging rights of winning the first cup final meeting between Arsenal and Chelsea.



Freddie Ljungberg and Ray Parlour scored the goals for Arsene Wenger's side in a 2-0 victory. 7/10 Bridge of sighs April 2004: Arsenal 1-2 Chelsea



Losing at home to your rivals is hard enough to take. Being eliminated from the Champions League certainly cranks it up a notch or two.



But imagine the feeling when all of the above is caused by a late winner from Wayne Bridge.



In six years at Chelsea the former England left back would only score one goal, and it guided them to the Champions League semi-finals. 8/10 Fisty Cups February 2007: Chelsea 2-1 Arsenal



Five years on from their first Cup final meeting, the teams faced one another again in the League Cup.



Jose Mourinho's Chelsea would triumph with a 2-1 victory, but the game had more to it than the three goals scored, two of which from Didier Drogba.



Kolo Toure, Emmanuel Adebayor and John Obi Mikel were all given their marching orders following a brawl late in the game. 9/10 Van the man October 2011: Chelsea 3-5 Arsenal



Less memorable than Kanu's efforts, perhaps, but Robin van Persie also struck three times in an Arsenal comeback at Stamford Bridge.



Chelsea led 2-1 at the break through goals from Frank Lampard and John Terry, before Andre Santos and Theo Walcott turned the game on its head and put the Gunners 3-2 up.



Juan Mata would bring the scores level with ten minutes to go, but Van Persie struck his second and third goals in the final five minutes to seal a famous win for Wenger's side. 10/10 Humiliation March 2014: Chelsea 6-0 Arsenal



Arsene Wenger has never beaten a Jose Mourinho side, and he's never been further from doing so as he was last year.



Goals from Samuel Eto'o, Andre Schurrle, Eden Hazard and Oscar put Chelsea 4-0 up at the break.



Mohamed Salah and another strike from Oscar would finish the rout, on a day which also saw Kieran Gibbs wrongly sent off by referee Andre Mariner after a case of mistaken identity with team-mate Alex Oxlade-Chamberlain.



Alongside their 8-2 defeat to Manchester United at Old Trafford, this remains Arsenal's joint-heaviest defeat under Wenger. 1/10 Chapman's champions set the mark November 1930: Chelsea 1-5 Arsenal



To this day, the clash back in November 1930 remains Arsenal biggest victory over the Blues. David Jack was the star that day, as his hat-trick fired Herbert Chapman’s side to a convincing 5-1 victory.



Arsenal would go on to win their first championship title that season. 2/10 Arsenal out gun Blues March 1958: Arsenal 5-4 Chelsea



The Highbury showdown back in 1958 was the highest scoring derby meeting on record between these two rivals.



Another David scored a hat-trick that day, with Arsenal's Herd netting a treble. 3/10 So good March 1973: Chelsea 2-2 Arsenal



One of THE goals between these sides kick-started a memorable FA Cup encounter.



Peter Osgood's exquisite volley in the quarter-finals opened the scoring as the sides played out a 2-2 draw at Stamford Bridge.



The Gunners would go on to win the replay 2-1. 4/10 Almost invincible February 1991: Chelsea 2-1 Arsenal



Everyone remembers Arsenal 'Invincibles' from the 2003-04 season, but many forget they came close to that feat back in 1991.



George Graham's side would finish champions come May, but his Gunners only suffered one defeat that season.



Terry Dixon and Graham Stuart scored the goals as Chelsea recorded a 2-1 victory at the Bridge.



Photo by Colorsport/REX 5/10 Kanu believe it?! October 1999: Chelsea 2-3 Arsenal



Forget just the derby, this is a Premier League classic in it's own right.



Arsene Wenger's side were trailing 2-0 with 15 minutes to go, only to be blitz the Blues with a sensational hat-trick from Nwankwo Kanu after Tore-Andre Flo and Dan Petrescu had put Chelsea ahead. 6/10 First finale May 2002: Arsenal 2-0 Chelsea



Arsenal's victory in the Millennium Stadium not only secured the FA Cup, but also the bragging rights of winning the first cup final meeting between Arsenal and Chelsea.



Freddie Ljungberg and Ray Parlour scored the goals for Arsene Wenger's side in a 2-0 victory. 7/10 Bridge of sighs April 2004: Arsenal 1-2 Chelsea



Losing at home to your rivals is hard enough to take. Being eliminated from the Champions League certainly cranks it up a notch or two.



But imagine the feeling when all of the above is caused by a late winner from Wayne Bridge.



In six years at Chelsea the former England left back would only score one goal, and it guided them to the Champions League semi-finals. 8/10 Fisty Cups February 2007: Chelsea 2-1 Arsenal



Five years on from their first Cup final meeting, the teams faced one another again in the League Cup.



Jose Mourinho's Chelsea would triumph with a 2-1 victory, but the game had more to it than the three goals scored, two of which from Didier Drogba.



Kolo Toure, Emmanuel Adebayor and John Obi Mikel were all given their marching orders following a brawl late in the game. 9/10 Van the man October 2011: Chelsea 3-5 Arsenal



Less memorable than Kanu's efforts, perhaps, but Robin van Persie also struck three times in an Arsenal comeback at Stamford Bridge.



Chelsea led 2-1 at the break through goals from Frank Lampard and John Terry, before Andre Santos and Theo Walcott turned the game on its head and put the Gunners 3-2 up.



Juan Mata would bring the scores level with ten minutes to go, but Van Persie struck his second and third goals in the final five minutes to seal a famous win for Wenger's side. 10/10 Humiliation March 2014: Chelsea 6-0 Arsenal



Arsene Wenger has never beaten a Jose Mourinho side, and he's never been further from doing so as he was last year.



Goals from Samuel Eto'o, Andre Schurrle, Eden Hazard and Oscar put Chelsea 4-0 up at the break.



Mohamed Salah and another strike from Oscar would finish the rout, on a day which also saw Kieran Gibbs wrongly sent off by referee Andre Mariner after a case of mistaken identity with team-mate Alex Oxlade-Chamberlain.



Alongside their 8-2 defeat to Manchester United at Old Trafford, this remains Arsenal's joint-heaviest defeat under Wenger.

However, Sporting have since bought out BES after taking advantage of the firm’s troubled financial situation. BES was facing insolvency due to problematic loans to companies linked to its controlling family but it was bailed out by the Portuguese government, which injected 4.4billion euros.

With BES looking to raise money to pay back the state, they are understood to have sold their 40 per cent share in Carvalho to Sporting at a reduced market rate. So with BES no longer involved and Sporting having saved money on purchasing full rights to their player, Carvalho is now available at a lower price.

Significantly, the £21.5m figure quoted in Portugal this morning is lower than the fee Southampton are demanding for Morgan Schneiderlin.

With Southampton set to miss out on Champions League qualification, Schneiderlin is expected to try and force through a transfer away from the south coast but Saints are refusing to budge in their £25m valuation.

Wenger is believed to prefer Schniederlin but the decrease in Carvalho’s price could prompt a change of heart.

The Arsenal manager is also impressed with Francis Coquelin’s emergence in the holding midfield role ideally suited to Schniederlin and Carvalho but it is understood there are some individuals close to Wenger urging him to strengthen this area regardless.



