Chatman is a WR, Wahle is a lineman... two completely different positions..
Also, I don't know what Antonio Chatman you were watching last season, this kid came basically out of nowhere and established himself as a better slot receiver than Ferguson has done since ol' Fergie was drafted to be a premier possession receiver to compliment Freeman, then Driver, and now with Walker playing himself to the league's elite last year, has kind of made me think twice about why this kid has been given so many chances.
As long as the offensive line has Rivera, Clifton, and Flanagan they'll be fine and still be among the best.
Deadbolt is right though, Chatman does suck as a LG, since he never played it.