It depends on what Milwaukee tries to do, but it is most likely that we get Dalembert, Speights, Iguodala, Green and Miller, with Ratliff, Evans, Marshall, Ivey and Williams playing as backups.
This is a good chance to see how well they can integrate Speights into the offense against a relatively weak team, with a very slim shot of making the playoffs. The Sixers really have to get this win, they need a cushion over Miami before we play Cleveland twice and Boston to end the season.
Really the rest of the season is going to be about winning without Thad's 20 ppg. Since I've been wanting Speights to get more time, and the coaching staff has been reluctant, the injury will force their hand. Really they don't really have another player who can come in and possibly give them those 20 pts. In theory it should actually make the Sixers better, since Thad wasn't much of a defensive stopper anyway. Speights won't get those easy baskets that Thad did by running the floor, but he did shoot some low-post moves when he was given the ball against the Hawks.
The team should rebound better as well as block out with Speights in instead of Thad. We should expect the interior defense to pick up a bit, encouraging opposing teams to take more outside shots.
Since the Sixers like to play Iguodala for nearly 40 min. a night, it's not much of a problem to find a replacement. It might very well be that Rush gets a chance. He did play well the last time he got into a game.