Chelsea have accepted a £37million bid for Juan Mata and immediately released the Spanish international to join Manchester United to complete the most dramatic deal of the transfer window.

Mata will undergo a medical on Thursday at United before completing the move that will see him more than double his £70,000-a-week Chelsea salary at Old Trafford.

Chelsea have been braced for a bid since Monday for Mata and finally received the offer triggering their acceptance and the release of the player.

The Premier League club are not expecting the 25-year-old to return to them and have already made plans for his replacements. A medical has been booked in for Thursday for Mata and personal terms accepted.

United chose a slightly unusual route to lodge their bid, using intermediaries, but Chelsea have accepted the offer as an official one and manager Jose Mourinho has sanctioned the move.

The bid, first revealed on Monday, came ahead of the champions Capital One Cup semi-final second-leg tie at home to Sunderland.

Mata’s father, Juan senior, and his representatives flew in from Spain on Wednesday morning after it became apparent an offer would finally be made.

They are keen for Mata to make the move after he fell out of favour under Mourinho which has placed his chances of playing for Spain in this summer’s World Cup Finals under threat.