jtravolta011311_01_X17.jpgJohn Travolta revealed that he's been approached to guest star on Glee and even though it seems Travolta would be a natural for the Golden Globe-winning Fox show, he hasn't said "yes" yet!

"They've asked ... But I don't know," the new dad told ET.

So what's holding him up? "When I do musicals I train for six to nine months sometimes a year in preparation," John said. "A show like that is an on-demand thing and I really have a criteria and pride ... I would wanna knock em' dead, and I don't think I can knock 'em dead in a week."

But we think the Grease and Hairspray actor is just being too modest!