Manchester United midfielder Nemanja Matic is considered a doubt to face former club Chelsea in the huge Premier League clash at Stamford Bridge later this month after injury forced him to withdraw from the Serbia squad for upcoming internationals.
Matic had been due to represent his country in League C Group 4 clashes against Montenegro and Romania. But United have confirmed that he has already returned to England due to an unspecified injury to 'continue his rehabilitation under the club's guidance'.
The 30-year-old will look to recover under the watchful eye of medical staff at United's Carrington training complex over the coming 10 days.
He and Mourinho were on the losing side against their former club twice last season - in the Premier League at Stamford Bridge in November and in the FA Cup final at Wembley in May.
After a poor start to the season United currently trail Chelsea by seven points after only eight games. Now led by new manager Maurizio Sarri, the Blues are only being kept off the top of the table as a result of having an inferior goal difference to Manchester City.
Luke Shaw has also been forced to withdraw from the England squad through injury this month, although United do still have as many as 11 players representing 10 different countries all over the world in the coming days.
Man Utd's International Call Ups:
Marcus Rashford (England), Paul Pogba (France), Romelu Lukaku, Marouane Fellaini (both Belgium) David de Gea (Spain), Alexis Sanchez (Chile), Fred (Brazil), Victor Lindelof (Sweden), Sergio Romero (Argentina), Scott McTominay (Scotland) and Eric Bailly (Ivory Coast)