"Players sometimes go through these types of spells," said Giggs. "Ruud van Nistelrooy missed three on the trot.
"Not many people remember that but I do. The fourth one he buried it and probably didn't miss one again.
"Wayne is our penalty taker. He will be disappointed because he is a goalscorer who wants to score goals. But I am sure if we get another, he will take it."
Critics have been lining up to take pot-shots at Rooney since his midweek spot-kick woe and Roy Keane has joined the chorus.
"I think that will be the last penalty Rooney takes for United," said Keane. "Wayne has missed 10 now and that is far too many. Clearly, he is not up to it. Van Persie, I'm sure, will be delighted to take over that role."