Chelsea midfielder Juan Mata will only be allowed to join Manchester United if he hands in a formal transfer request to Blues boss Jose Mourinho, writes Guillem Balague in Spanish publication AS today.
Speculation surrounding Mata's proposed £40m move to Old Trafford has intensified over the past 48 hours, with United reportedly ready to smash their record transfer fee to persuade the Spanish international that he can rebuild his career with the Premier League champions.
Balague believes that negotiations between Chelsea and United over Mata have reached an advanced stage, but the fan backlash that may surround the Stamford Bridge star's departure is still a major stumbling block to a January move being finalised.
Mata may be finding regular first-team opportunities difficult to come by at Chelsea this season but is yet to go public with any desire to find a new team, something that Mourinho wants to happen before even considering selling a player who was the club's player of the season in each of his first two campaigns in West London.
Mourinho is open to the possibility of allowing Mata to join United at the right price though according to Balague, who believes that the Chelsea boss can see the benefit of strengthening the Red Devils with title rivals Manchester City and Arsenal still on their fixture list.
The 25-year-old's position in Spain's plans for the World Cup is also thought to be a factor in exit talk, with the Blues braced for an official offer before the end of this week.