The Australian produced a celebration for his goal which was later revealed was for his elder brother, who has recently been sent to prison.
Moyes said: "Cahill has also been sick. He has done very light training, but they are all determined to play.
"Determination and desire has been the key to us this season. It is what I require, and the lads who have been with me for a while are forcing the others into the attitude - we have a great team spirit."