I hate to break this to you, but Haas will never average 10 rebs per game. Rebounding is about positioning, reaction, knack for the ball and very little to do with height (A couple of good example is Barkley & Rodman). He doesn't have any of those qualities.
He need to be tougher for sure, but I think he is losing some confidence as his role is diminishing at critical moments of certain games. He will need to get over this, as we will need a smaller and quicker liner up against certain smaller and quicker teams like Nova, Louisville and MN. I think against these teams we need Biggie, VE, DM, CE and PJ starting. Against bigger teams it should be Hass, Biggie, VE/DM (whoever is playing better), CE and PJ starting.
Without Biggie next year, Haas rebounding number won't go up much at all, and that's why I'm afraid that rebounding for next year will be our biggest deficiency unless we recruit one. I think we have 2 schollies available with Biggie leaving, so we need to use it wisely. Otherwise we will get out-rebounded on a pretty regular basis, as I'm not seeing anyway anyhow with next year roster making this up with Biggie leaving.