I agree with your view that they need a big to play next to Chet. Also, they desperately need rebounding. If you look at their stats during the regular season, they get out rebounded a lot. Also, in the last 2 losses to the Mavs, they got completely destroyed on the boards. Chet is tall and all, but it seems he doesn't box out well enough and/or simply can't get those boards. Markenen seems like a good option, as he averaged over 8 rebounds last season and can shoot the 3 (almost 40% 3 pt shot). He is also young, so will probably have the legs to run the floor and play at a fast pace along OKC's young roster.