Manchester United are on the verge of completing a deal for Chelsea midfielder Nemanja Matic, after agreeing a fee in the region of £40 million, sources have told ESPN FC.

The club are hoping to announce a deal for the Serbia midfielder in the coming days and he could make his debut against Sampdoria in Dublin on Wednesday or in the UEFA Super Cup against Real Madrid next week.

A leaked picture on Twitter allegedly showed Matic already wearing a United training top. Sources told ESPN FC that he underwent a medical at Carrington on Sunday and United should be able to announce the deal in the next 24 hours once the final details are completed.

The 28-year-old will become Jose Mourinho's third signing of the summer after the arrivals of Victor Lindelof from Benfica and Romelu Lukaku from Everton.

Mourinho has made no secret of his desire to add more players to his squad before the end of the transfer window and, after Matic's arrival, he is set to target one final addition.