Manchester United have made a club record bid of £40m for Chelsea's Juan Mata through a third party, according to Sky Sports News sources.
Neither club have confirmed the offer but the playmaker missed training today and it appears that the first move has been made in what would be one of the biggest transfers of the season.
The player himself is understood to have told friends he is leaving Stamford Bridge, although United manager David Moyes refused to comment on the proposed transfer after seeing his side defeated on penalties by Sunderland in the Capital One Cup semi-final, second leg tie at Old Trafford.
All parties are keen for the transfer to go through, according to Sky Sports' Spanish football expert Guilleme Balague, and there has been speculation that a medical will take place before the weekend.
United need a filip in a disappointing season and the signing of Mata - which is likely to break the club's transfer record - would be a serious statement of intent.
Chelsea are understood to be happy to sell as manager Jose Mourinho has too many attacking players in his squad and prefers other options to the Spaniard.
The club would also make a significant profit on a player they signed for £23.5m from Valencia in 2011.
For Mata the transfer would give him an opportunity for much more playing time with the World Cup in Brazil looming this summer.
However, transfers between Chelsea and Manchester United in either direction are few and far between and the Premier League's top clubs prefer not to sell to direct rivals.
Balague says all parties want the transfer to go ahead.
Balague revealed on Revista de La Liga: "The idea is that Mata, who Chelsea are happy to let go, goes to Old Trafford in this transfer window.
"I am under the impression that a deal will be reached because it benefits everybody.
"United need quality, Mata needs to get out of the situation he is in and it would reinforce United for their meetings with (Chelsea's title rivals) Manchester City and Arsenal, which is clever from Jose Mourinho."