(CNN)At Super Bowl LVII on Sunday, while other rival fans might prefer to keep their distance, Kansas City Chiefs fan John Gladwell will sit with Philadelphia Eagles supporter Billy Welsh in the stands of State Farm Stadium -- but it's more than friendship that bonds the two men.
After serving in the Marines together some 20 years ago, the pair stayed in touch on Facebook, but didn't speak regularly. But in 2019 when Welsh wrote on Facebook that he needed a kidney, it was Gladwell who got himself tested, and on discovering he was a match, made the lifesaving offer.
"It meant the world to me. I was speechless. John Gladwell is my hero," Welsh told NBC's "Today" show. The kidney transplant required 10 hours of surgery, but Gladwell made sure to remind himself it was "just another day."
On Gladwell's part, he said he extended his offer because Welsh has a son around the same age as his own grandson.
"I wasn't going to let his son grow up without his dad being there for everything," Gladwell added.
After hearing the story, Eagles team president Don Smolenski contacted the Chiefs, and the teams worked together to send the men to Arizona to watch the game together.