Manchester City defender John Stones has been dominated out for up to two weeks with a hamstring injury endured on England responsibility.
“I do not know when he will appear back again but I think perhaps 10 days, two months,” claimed City boss Pep Guardiola.
2nd-positioned City host fifth-placed United in the Premier League at Etihad Stadium at 14:00 BST.
City also engage in Southampton in the league and FC Copenhagen two times in the Champions League right before experiencing Liverpool on 16 October.
Midfielder Kalvin Phillips, who has designed only a person physical appearance for City considering that becoming a member of from Leeds this summer months, experienced shoulder surgical treatment during the international break.
The England squad for the World Cup is because of to be named on 20 October.
“He feels great. He is getting much better,” said Guardiola. “He took the right determination.
“Hopefully he can be back again in time to go to the World Cup.”