Im not saying Lopez is good. I really have not seen him play much, but his stats are not terrible.
http://espn.go.com/nba/player/_/id/3447/robin-lopez
He started 31 games in '09 and put up decent numbers. 8.4 points and 4.8 rebounds while only playing 19 minutes per game. That doesn't seem to be too bad. His stats have slid a little the last two years, but so have his minutes. His Player efficiency rating is pretty high at 15.23