Nemanja Matic an injury doubt for Manchester United's clash with Chelsea after withdrawing from Serbia squad

The 30-year-old midfielder has returned to Carrington for treatment of an unspecified problem

Manchester United midfielder Nemanja Matic has withdrawn from Serbia's squad for their Uefa Nations League fixtures in Montenegro and Romania due to an unspecified injury.

United confirmed Matic had returned to Carrington “to complete his rehabilitation”, leaving him a doubt for his and manager Jose Mourinho's return to Stamford Bridge to take on Chelsea in the Premier League immediately after the international break on October 20.

The news of Matic's return to United comes a day after Luke Shaw pulled out of the England squad for their Uefa Nations League double header against Croatia and Spain.

Matic has made eight appearances for United in all competitions this season and was sent off during his side’s hard-fought 2-1 away win over Watford in September.

Matic has been unable to prevent United struggling this season (Getty Images)

Earlier this month the Serb insisted that everyone at United remains committed to Mourinho, whose future has been thrown into serious doubt after public tensions with the board as well as several key players – most notably star midfielder Paul Pogba – were compounded by the club’s worst start to a league season for 29 years.

“The manager is trying to turn this [around], he is trying to make the team stronger and ready for the next challenge,” Matic said.

“I can say that in the club everyone is giving his best to do better for the team.

“It’s very hard but this is football, this is life. For sure, everyone wants to do better. We know that we didn’t play well the last couple of games. Everyone is trying to resolve this situation.”

Matic played under Mourinho at Chelsea for two years until the Portuguese’s sacking in December 2015, and rejoined his former boss at United in a £40 million deal in the summer of 2017.