Only 1 match has been confirmed for SummerSlam 2015 so far, and it’s Brock Lesnar vs. The Undertaker.
Other matches that might happen at SummerSlam 2015 are:
* Seth Rollins (c) vs. John Cena for the WWE World Heavyweight Championship
* Ryback (c) vs. Big Show for the WWE Intercontinental Championship
* Dean Ambrose, Roman Reigns & Sting vs. Bray Wyatt, Luke Harper & Mystery Partner
* Prime Time Players (c) vs. The New Day for the WWE Tag Team Championship
* Team B.A.D vs. Team Bella vs. Paige, Sasha Banks & Becky Lynch
* Dolph Ziggler vs. Rusev
* Kevin Owens vs. Cesaro
Sting might be introduced as a surprise partner in the tag team match. If WWE wants to do a regular 4 person tag team match, then they might do an injury angle with Ambrose and bring in Sting as the surprise replacement. Dolph Ziggler might face Rusev if he winds up his movie and is able to return in time. This might be changed to a mixed tag team match with Dolph Ziggler & Lana vs. Rusev & Summer Rae.
With Kevin Owens now being an upper mid-card talent, he’s expected to face Cesaro at SummerSlam 2015. Seth Rollins vs. John Cena won’t be a “Title for Title” or “Champion vs. Champion” match, but it is expected to be for the WWE World Heavyweight Championship.