John Smoltz's decision to have Tommy John surgery at 34 took place after a phone call from Tommy John himself

John Smoltz was able to pitch for nine additional seasons after undergoing Tommy John surgery at the age of 34 -- something he will always be thankful for. But it's the story behind the decision to have the procedure that's fascinating. 
According to The Athletic, (subscription required), when Smoltz figured he would retire in 2000 after sustaining a torn UCL, the thought of having the surgery wasn't exactly appealing.
"There weren't many 34-year-olds, in my mind, having Tommy John surgery," Smoltz told The Athletic. "I was going to be in the final year of my contract and I just figured that no one would want a 34-year-old who had Tommy John surgery. I just didn't think it was going to be worth it. I was pretty down and out and ready to call it quits."
But Smoltz's phone rang. On the line ... was Tommy John himself.
John reminded the Hall of Fame pitcher that he, too, was 34 when he had the procedure that was named after him.

"Hindsight's 20/20, but I'd have probably pitched [more seasons] with less pain," Smoltz said. "You know, we were going through the playoffs every year with the Braves. So I didn't really feel I had any options. I pitched as long as I could till it completely tore."
We don't know every detail of the phone call, but after the conversation, Smoltz had the surgery.
Smoltz had four All-Star selections following the 2001 season and was in MVP and Cy Young Award conversations. He remains the first and only pitcher in the Hall of Fame to have undergone Tommy John surgery.