John Cena is set to defend the Undisputed WWE Championship against Cody Rhodes in a Street Fight at SummerSlam 2025. On last week's SmackDown, fans witnessed a different side of The American Nightmare as he behaved more aggressively than usual. The same attitude could continue this week, causing a massive change to The Biggest Party of the Summer, as John Cena may succumb to Rhodes' wrath once again.During the contract signing last Friday, Cena came out sporting an unusual demeanor and tried to back out of the scheduled title match for SummerSlam. The Never Seen 17 claimed his filming commitments prevented him from competing at the upcoming PLE and proposed postponing the title match to a later date. However, a visibly angry Cody Rhodes ended up launching a beatdown on Cena, leaving him unconscious in the middle of the ring.In a shocking sight, The American Nightmare forcefully placed John Cena's signature on the contract and revealed that the match at SummerSlam would be a Street Fight. The Last Real Champion may not appreciate the bout being made official against his will and may attempt to back out once again tonight.While Cena is not scheduled to be in attendance this week, he could make an unannounced appearance to respond to The American Nightmare. However, Rhodes might double down on last week and launch another attack on The Last Real Champion. This time, he could take it a step further and end up heavily injuring Cena, putting the latter on the shelf for the foreseeable future.The American Nightmare's untamed aggression might end up costing him his SummerSlam title shot, as Cena might not be cleared to compete two weeks later, at The Biggest Party of the Summer, after tonight. That said, it is only speculation at this point. Fans will have to tune in tonight to see what the Triple H-led creative team has in store for SmackDown.WWE veteran reveals the potential reason behind John Cena's shocking heel turnSpeaking on a recent episode of Writing With Russo, former WWE head writer Vince Russo discussed the potential reason behind John Cena's heel turn at Elimination Chamber: Toronto. Russo suggested backstage tension among management led to the moment.The veteran believed The Rock originally wanted Cody Rhodes to turn heel but could not come to terms with the rest of management, leading to Cena's heel turn."Well, for starters, I think it was plan B. Because Rock has told us this, Cody has told us this. Rock wanted Cody to turn heel and they poo-pooed it. So then Rock's next idea was John Cena turning heel, which was plan B. I also think at that point, Rock was a little bit p*ssed off because this was the second WrestleMania in a row that they didn't listen to him. So, I think at that point, he said, 'Well, you're on your own. There are other things that I could do rather than hang around here and be shot down every time I come up with something.' So, at that point Rock takes himself out of it creatively." [From 1:58 onwards]Will John Cena walk out of SummerSlam with the title still around his waist? Only time will tell!