Before the Clippers and Grizzlies tip off at 6:30, you can watch the Heat and the Bucks. Of course, it won't be a lot of fun, since the Heat are going to crush the Bucks, even in Milwaukee, but you can still watch them if you want. The game starts at 4 on TNT.
Over on NBA-TV at 5:30, the Nets and Bulls play Game 3 in Chicago, with their series tied at 1-1. That one could be a pretty good game, but it will only be to half time by the tip off of the Clippers-Grizzlies, so you'll just have to follow the score in the second half.