"He was always there to catch me as long as I wanted," Cole said of his father. "Without him, I don't think I would have become as good."
Cole's parents still reside in California. They get to see their son play when they make an occasional trip to Philadelphia and also look forward to the Phillies' visits to the West Coast.
After one of Cole's starts, however, don't expect to hear intense conversations between he and his father about how to analyze hitters or analyze Cole's pitching motion. His dad just enjoys watching the game, Cole said.
"He's like, 'You know what? You surpassed me after high school,'" Cole said. "'You've learned everything.'"
During Cole's Little League days, the lefty was proud of his ability to pitch with accuracy and field the ball cleanly, but sometimes struggled with hitting. He remembers having a tendency to back out of the batter's box as a pitcher started his windup.
That's when Gary stepped in with words of encouragement.
"'Swing the bat and keep your eye on the ball,'" Cole recalls his father saying.
While Cole was growing up, Gary worked as a school district's financial adviser and was able to leave his job early to see his son's games.
"That was quite nice, just to know that your dad is in the stands," Cole said. "A lot of people don't have that opportunity."
When Cole does get a chance to return home to California to visit his parents, he sees that some things haven't changed.
Even though the 24-year-old Hamels has become a cornerstone of the Phillies' starting rotation -- tied for the team lead with six wins and holding a 3.36 ERA, the lowest among Phils starters -- the elder Hamels still wants to play catch.
"I'm like, 'Dad, I can't play catch with you right now,'" Cole said. "'I throw too hard for you.'"