Cahill will be out of action for around eight weeks, following an medial ligament injury.
Moyes said: “It’s a big blow for us as he has been such an influential performer
“We will miss him greatly and you can’t replace his goals. He is a huge part of our team, a real important member.
“He has got so many all round strengths – good in the air, and he has got the drive.
“But it has happened now and we have just got to get on with it.
“What we want now is to see someone else step up to the plate and help us like Tim does.”
