Everton’s Australian midfielder Tim Cahill will be be out of action until January after injuring his knee at the weekend.
Cahil was stretchered off after colliding with Everton team-mate Lee Carsley during his side’s 1-0 Premiership defeat against Aston Villa on Saturday.
“I can’t put into words how much he’ll be missed for the next six to eight weeks,” said Moyes.
“He will do everything that he can to get back from this injury as quickly as possible, he will want to make sure that he is not out for eight weeks.
“He is tough and he will be pushing himself all the time. That is an asset.
“I think we were all a bit concerned that it could have been worse than it actually is. The problem is with his medial ligament and there is also a little bit of damage to the cartilage.
“He might have a slight tear. But we are thankful that it is not his cruciate as that would have been it for the season.”