Nemanja Matic is a "Jose Mourinho player", the Manchester United boss has declared.
The 29-year-old moved to Old Trafford after a very positive spell at Stamford Bridge.
He is Mourinho's third summer signing.
The Serbian will wear the No.31 jersey left vacant at the club since Bastian Schweinsteiger.
"Nemanja is a Manchester United player and a Jose Mourinho player. He represents everything we want in a footballer; loyalty, consistency, ambition, team player," Mourinho told the club's official website.
"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."
