Jim simply wouldn't let Heath quit baseball.
And Heath was ready to hang it up on a couple different occasions. When the college scholarship offers from Division I schools didn't come, and then when he wasn't drafted out of junior college, Heath was ready to enlist in the Marines.
"I was like, 'Man, my dreams are gone,'" Heath said. "The scouts were talking about me, and if they're not going to draft me, I must not be good."
But every time Heath was ready to join the service, he had a lunch with his father. Jim always talked Heath out of enlisting and continued to push his son to pursue his baseball dreams.
That doesn't mean Jim was against the military. In fact, he was a Marine for most of his adult life.
Heath recalled one story his father told him that epitomizes his no-quit mentality.
One day during boot camp, the Marines brought in a marathon runner to provide quite the physical challenge for the cadets.
"[My dad] told himself he would not stop running alongside this marathon guy," Heath said. "He was dying, and guys were falling off left and right by the end of the day. The whole point was for the marathon runner to run and let every cadet basically fall off, and then it was done.
"My dad was the only one who stayed with him the whole time."
Jim also pitched while in the Marines, and he clearly saw something in Heath that showed that he had the tools to make it in professional baseball.
After all, Jim had been watching his son since Little League, where he used to try to hide in the outfield bleachers because he had a superstition that Heath would pitch poorly if he knew his dad was in attendance.
"I always knew where he was," Heath said. "I just led him on. I said, 'OK, Pop. If you think that works, I'll pretend like I don't know about it.'"
Still, Heath's road to the Majors wasn't easy.
After going undrafted in 1998 following his stint at Rancho Santiago Community College in California, Heath started to play summer ball, at his father's encouraging. That led to Heath being signed by the Mets as a Minor League free agent -- for $500 -- and then spending nine years grinding it out in the Minor Leagues.
"I saw a bunch of guys go up and down," Heath said. "I spent five years in Triple-A just sitting there waiting for my spot, seeing everyone else go up but me."
Sticking it out in the Minors eventually paid off, though, as the Mets first called Heath up in 2004 before he eventually found a home in San Diego when he was traded to the Padres after the '06 season.
"That goes back to my dad saying to me, 'Dude, never give up,'" Heath said. "You can get knocked back down, but don't give up."
Heath made his big splash last season when he led the National League with 42 saves. That also earned him a spot on the NL All-Star team, an experience he was able to share with his father and the rest of his family.
Heath is also widely regarded as a fan and clubhouse favorite because of his enthusiastic and friendly personality, which he again credits to his father.
"I'll sit and talk to you, and I'll treat everybody like I would treat my own teammate," Heath said. "For the majority of the San Diego fans here, or even around baseball, people kind of realize, 'Dude, Heath Bell's pretty cool.' It's all because my dad told me [to] treat everybody like they're your best friend."
With the help of his dad, Heath is now living the big league dream. But it's been Heath's turn to repay the favor in recent months.
Jim was diagnosed with Stage 4 lung cancer earlier this year just as the Padres were starting Spring Training.
"It's hard," Heath said. "It's hard for my mom to talk about it, and it's hard for my dad to talk about it."
Jim went through more than two months of chemotherapy and radiation, where his weight dipped to around 130 pounds. The next steps in his treatment will be determined in the coming weeks.
When Heath noticed his father was mentally struggling, he wouldn't let Jim give up.
"I honestly think he was losing faith, and he was giving up and he was just waiting to die," Heath said. "I truly believe that. I yelled at him over the phone after [the Padres'] Houston trip [in May]."
Heath shared those feelings with his daughter, Jasmine, who then started calling Jim every day.
Since the extra push from Heath and Jasmine, Jim's spirit has been on a huge upswing.
"He kind of needed his youngest son and one of his grandkids to turn him around," Heath said. "He's done better ever since my daughter's been calling him. I think he's starting to find a will to live again."
Jim never allowed Heath quit baseball. And now, Heath won't allow his dad to quit on life.
"Sometimes you need a little kick in the butt, for whatever reason," Heath said. "He needed a little butt whoopin'. Everyone knows I'm not afraid to kick some butt here and there, because my butt's been whooped. I whooped him back in shape, so hopefully he keeps this thing going, or I'm going to whoop him back in shape again."
After all, Heath is his father's son.