United will face Celtic at Parkhead on Tuesday, in the UEFA Champions League.
The Scot wants to save some of his players for the top of the table clash with Chelsea the following Sunday.
Ferguson said: “I have obviously got to think about the Chelsea game when I pick my team to face Celtic and there will be one or two changes to the side.
“Players like Gabriel Heinze will come into contention, but we want to come back from Glasgow with qualification guaranteed.
“We took a bit of a risk in Copenhagen and it went wrong for us.
“We want to get a result to make sure we qualify, but the Chelsea game will have a bearing on the team I pick.
“I think it is good that we have a hugely important game at Celtic ahead of playing Chelsea. It will be good preparation for the Chelsea game because there will be a real intensity about the occasion in Glasgow.
“Celtic have fantastic support and we have got to cope with that because it gives them a definite lift.
“But we’ve got players who have seen these types of occasions and I am sure they will cope with it this time as well.”
