As noted, Sting is expected to get involved in the current Roman Reigns vs Bray Wyatt feud, which will lead to some type of match at SummerSlam.
Read Also: Plans for a Major Name Returning to WWE, Concern for Reigns at SummerSlam?
WWE has been discussing a variety of match plans for SummerSlam, including Sting and Roman Reigns vs Bray Wyatt and Luke Harper. WWE has also been talking about adding a third, new member to The Wyatt Family since Erick Rowan is out of action, and making the match at the PPV a 6 man tag match including Dean Ambrose.
In an update to the above, The Wrestling Observer is reporting that WWE wants Sting’s return to be a big surprise, so he is not expected to be brought into the story line until late in the game, just before SummerSlam.