Manchester United have confirmed they have completed the signing of Nemanja Matic from Chelsea on 31 July.
The Serbian international will sign a three-year deal with the Red Devils. The 20-time English champions have an option to extend his stay at Old Trafford by further year.
A statement on United's official website read, "Manchester United is delighted to announce the signing of Nemanja Matic from Chelsea on a three-year contract, with an option to extend for a further year."
Matic rejoined the west London club from Benfica in January 2014, when Jose Mourinho was in charge at Stamford Bride. The midfielder will now reunite with his former manager at his new club, United.
The 28-year-old becomes the Old Trafford club's third signing of the summer transfer window. Matic follows Swedish international defender Victor Lindelof and his former teammate Romelu Lukaku to United. The latter two arrived from Benfica and Everton respectively.
The former Benfica midfielder has revealed the opportunity to work under Mourinho was hard for him to turn down. He went on to thank Chelsea and their supporters following his switch to United.
"I am delighted to have joined Manchester United. To work with Jose Mourinho once again was an opportunity I couldn't turn down," Matic told his new club's official website.
"I have enjoyed my time at Chelsea and would like to thank the club and the fans for their support. I cannot wait to meet my new team-mates and to start training with them.
"This is a very exciting time for the club and I am looking forward to playing my part in creating more history for this great club."
Mourinho hailed his signing as "a Jose Mourinho player." He said, "Nemanja is a Manchester United player and a Jose Mourinho player. He represents everything we want in a footballer; loyalty, consistency, ambition, team player."
"I would like to thank him for his desire to join us because without that, it would be impossible to have him here. I am sure our players and supporters will love him. A big welcome to our new number 31."