Pekovic would be a fine addition if you want a center with the following attributes: a) no rim protection; b) below average rebounding; c) no offensive range beyond 5 feet from the rim; d) no passing skill; and e) the foot speed of a three-toed sloth. I would have also said: f) injury prone, since he has missed a total of 81 games the past two seasons ... but you already mentioned that issue.
Given all those minuses, Pekovic would be a serious downgrade from Lee, Amir Johnson, Zeller, KO or even Sully at center.