Sir Alex Ferguson’s men are in second place, four points behind Roberto Di Matteo’s pacesetters as they look to close the gap on the Blues with victory at Stamford Bridge.
United have fallen behind in eight of their 12 games so far this season and the Welshman admits the Red Devils cannot afford to concede first against Chelsea.
“There are two ways of looking at it,” said Giggs. “Obviously we are pleased that we are able to come back and have shown great character in those eight games.
“But you cannot keep relying on the lads up front to score the goals. It is something we have looked at and are still looking at.
“It has happened again against Braga but against Chelsea if we go behind it will be tough to come back.”
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