MOSCOW — Manchester United manager Jose Mourinho hopes Marouane Fellaini will be out for only about two weeks.
Fellaini was hurt by a hard tackle from Shane Long during United's 1-0 win over Southampton on Saturday in the Premier League.
With Paul Pogba also injured, Fellaini's absence has left a hole in the midfield heading into the Champions League game against CSKA Moscow on Wednesday.
"Fellaini was lucky, it could be a much worse situation but in a moment where we don't have Pogba and (Michael) Carrick, Marouane becomes even more important than he always is," Mourinho said Tuesday. "The solutions are not many.
"It's a difficult situation for us, but I expect Fellaini not to be out for a long time."
With Belgium already qualified for the World Cup, Mourinho hopes Fellaini will be rested during the international break next week.
"He's not under pressure in a big match for Belgium so I hope he'll be back with us," Mourinho said.
Fellaini will miss the Premier League game against Crystal Palace on Saturday, but could be ready two weeks after that for the league game against Liverpool.
In Moscow, United faces a team which is fourth in the Russian league and trying to bounce back from defeat in the Russian Cup on Wednesday. Both United and CSKA won their opening Champions League games in Group A.
CSKA coach Viktor Goncharenko said Ander Herrera could take on Fellaini's role in midfield alongside Nemanja Matic, but added he didn't expect the switch to leave any weak points.
"Big clubs can always replace their top players when they're out," Goncharenko said. "Matic and Fellaini is one kind of game, Matic and Herrera is another, but it doesn't mean their level is going to drop. Maybe something will change around set pieces, but there won't be any weakness."