The 40-year-old was rested for United's 4-1 victory over Aston Villa on Saturday.
However Saha, who played with Giggs during his spell at Old Trafford, believes that the midfielder's experience would be a vital asset against Bayern.
"Giggs knows his body so he knows when to play and not," Saha told the Manchester Evening News.
"You can see that when the team is not that strong in midfield sometimes they try to give the terrific passes and clever things but they're done much too slowly which doesn't allow the wingers and strikers to play and get one-on-one situations or counter attack quicker.
"This is the power of Giggs, he knows how to do that like the way Paul Scholes used to do it because of his experience and talent. He's got the ability to do those things because he has immense talent. Some of the other players this season haven't been able to do what he can do."