Jose Mourinho hailed Nemanja Matic as "a genius" following his Manchester United debut against Sampdoria.
Matic completed a £40million move to United from Chelsea on Monday, linking up with Jose Mourinho for a second time after the Portuguese brought him to Stamford Bridge in 2014.
The Serbia international signed a three-year contract with an option for a further 12 months and played the opening 45 minutes on Wednesday, featuring at the base of United's midfield as they beat Sampdoria 2-1.
And Mourinho told MUTV: "This is Matic.
"In my opinion, to play simple in that position is genius, and he's a genius because he makes everything so simple, the team runs, the ball runs, he's fantastic in his position.
"The way he plays, he plays with his brain, of course he needs physicality to be a at the top of his game, but obviously no pre-season, no pre-season, it's not easy."