Yao Ming's first 4 games: http://www.basketball-reference.com/players/m/mingya01/gamelog/2003/ Don't really know enough about him in college, but I think a factor is that Bennet, unlike most high picks, is on a team that is actually trying to get into the playoffs this year. So, he's not gonna get too many opportunities to play through his mistakes before the coach goes with a veteran.
Still early, I think they like the pairing of him and Irving. Given time maybe they can develop into a nice 1-2 punch.