In WWE.com's Raw results, they're saying that John Cena was simply "grazed" after John Bradshaw Layfield appeared to have crashed an automobile into him at the end of the show. Cena is fine enough in the storyline to fight JBL in their NYC Parking Lot Brawl match at The Great American Bash next Sunday.
Here is what WWE.com wrote regarding Cena:
"After knocking Cena unconscious, Layfield propped him up and attempted to smash a car into the prone Superstar. Luckily, John Cena managed to escape at the last minute and was only grazed, meaning that Cena vs. JBL will still take place on Sunday night."