"I would love to see Giggs as United's manager for many years but if I'm logical I would say it's a big risk right now in terms of experience," Saha told talkSPORT.
"You can see that in 10 months United might have to make another decision, get rid of him and say, 'no he has a lack of experience'. It's a different job and it's a big task.
"It's not like the situation where [Pep] Guardiola had a little experience of being with Barcelona's second team. He was able to experience that, maybe it was a lesser level, but at least he knew more [what it was like]."
Saha played alongside Giggs for United between 2004 and 2008.