And to be honest, as much as I love him, there is hardly a difference between JO and Perk. They are very similar players in many ways.
Over the last 1+ season, Perk has been terrible. Any weakness at center this team currently has would be no better if Perk was here. Not sure if he still has room to get better from his knee injury, but to be honest, I think he is just a very mediocre player at this point. His only real skill is defending one of the 3 good post centers left in the league.