"I gotta be honest: I don't know what (the New York Jets) really were thinking," Kelly told NFL Network's "NFL Total Access" on Thursday. "Mark Sanchez is a quarterback who's going to be sitting there every single game if he plays bad, and No. 1, you know Jets fans -- they're going to start booing."
"I think (there's) a lot of pressure on Sanchez to not only start off hot, but continue game after game after game playing steady," Kelly said. "If he doesn't, you know you're going to hear the boo birds. People want Tim Tebow in there.
"I like them both. I thought Sanchez was a very good quarterback coming on. If I was a general manager or president or owner of the team, I wouldn't have done that (trade) unless I got rid of Sanchez. But I think he's a good enough quarterback to be there.
"Tim Tebow's a great athlete who's going to be a big plus for somebody. But in New York? I'm not sure."