Source: The Wrestling Observer
As previously mentioned, The Big Show was scheduled to return on RAW last night, but was not used on the show. Word is that Show is still healing from his knee injury, and was still limping around backstage at WWE Money in the Bank. WWE had wanted him back as soon as possible to start an angle for SummerSlam.
WWE tapes RAW tonight, and then two weeks of SmackDown on Wednesday and Thursday and the feeling is that he'll appear on at least one of the shows to get the angle started. If not, he's still injured and they don't want him back yet because of that.