Cody Rhodes will challenge John Cena at WWE SummerSlam to hopefully win back the Undisputed Championship that he lost at WrestleMania 41. However, he might lose due to an unexpected star's interference.At Night of Champions 2025, Cody Rhodes defeated Randy Orton in the finals of the King of the Ring Tournament to become the number one contender for the Undisputed WWE Championship. He ensured John Cena didn't postpone the match by forcefully making him sign the contract on SmackDown last week. He will have a great chance to win back the company's most prestigious title soon, but a ghost from the past might interfere to ensure his loss.On last week's WWE SmackDown, The American Nightmare had a brief confrontation with Solo Sikoa, who asked for help as he was getting arrested as part of his onscreen storyline against Jacob Fatu. He chose not to help the heel, which could backfire if the United States Champion and his teammates take it personally.Solo Sikoa's storyline with Jacob Fatu will likely conclude at the upcoming premium live event, so he could interfere in the main event of SummerSlam to take revenge on Cody for not helping him on the latest edition of the blue brand. This could rekindle their storyline from last year and deliver a moment fans wouldn't expect.This scenario might help John Cena retain his title, but fans should note that it is currently speculative and has not been confirmed.What could happen when Cody Rhodes battles John Cena at WWE SummerSlam 2025?Considering Cody Rhodes and John Cena are two of the top stars of the company, and their match at The Biggest Party of The Summer will have no disqualifications, it may be safe to assume that it will not be a clean match.If Triple H plans for Cena to retain the title, an interference from a potential ally like Solo Sikoa or perhaps from Travis Scott could help ensure that The American Nightmare doesn't lose clean.In a surprising turn of events, John Cena could turn babyface after losing clean to Cody Rhodes at WWE SummerSlam 2025, thus ending his run as the company's top heel. Who knows? Fans could even witness a double turn in the main event of the upcoming premium live event.