United face second placed Valencia in the Champions League at Old Trafford on Tuesday night and a point from that game would guarantee first place.
“It is quite clear,” said the veteran goalkeeper.
“We are through now but we want to get top spot in order to avoid any of the bigger teams in the earlier rounds.
“That is what we need to do against Valencia.”
United could become the first team to go through the group stage without conceding a goal if they manage to keep a clean sheet on Tuesday.
He added: “So far we have not played against the biggest teams in the Champions League. Maybe that has something to do with it.
“When you start playing a higher standard of opposition it is going to become more difficult.”
