Frank's advanced stats are pretty good. His player efficiency rating in conference games was 22.6 (barely behind Garcia's rating). If he qualified (in terms of minutes) for the leaderboard, he would be #1 in offensive rebound percentage and #4th in total rebound percentage in the conference. He managed this while being significantly undersized compared to other centers in the league. If he gets the ball near the basket, he puts it in with a high completion rate. And, as we've seen, he is very good at putting in missed shots.
He definitely will have some interest even if teams are looking for him to play only about 15-20 minutes per game.