During the July 30th 2021 edition of WWE Smackdown, there was a contract signing segment for Roman Reigns vs. Finn Balor in a Universal Title match at Summerslam. However, Baron Corbin attacked Balor and attempted to sign the contract. John Cena then ran down to the ring and attacked Corbin. Cena grabbed the contract and signed it to make himself the official opponent for Reigns at the PPV.
— WWE (@WWE) July 31, 2021