A number of Manchester United players have reportedly grown frustrated with manager Jose Mourinho's continued faith in Nemanja Matic.

Matic has been an almost-constant feature of the United team since his arrival from Chelsea last summer, making 63 appearances across all competitions including 14 already this season.

However, the Serbian's form has been questioned so far this year and he was criticised for his role in Manchester City's final goal during Sunday's 3-1 derby defeat at the Etihad Stadium, having left Ilkay Gundogan unmarked inside the area.

The Times reports that some members of the playing and backroom staff now believe that Matic is untouchable regardless of his form and are unhappy with Mourinho's refusal to drop the 30-year-old.

Mourinho has signed Matic on two separate occasions in his career, first during his second spell with Chelsea and then again 12 months after his arrival at Old Trafford.