When Carlos Lopez was a kid, he sneaked into the Oakland Coliseum parking lot to mingle with A’s players and get some autographs. Now he’s serving up pitches to his former hero, Jose Canseco, in home run derbies.

It’s a testament to Lopez’s tenacity, and a comment on the strange career arc of Jose Canseco. He still makes headlines these days, but he does so mostly as a novelty act, not as the dashing sports figure he cut when the A’s were playing in World Series.

When Lopez was about 13, a friend told him a secret. The kid and his brother had cut a hole in the Coliseum’s perimeter fence, right under the overpass leading from the Coliseum BART station. For the next several years, Lopez and his brother would walk like 30 blocks from their home in another part of Oakland and sneak into the lot on game days.

Mind you, they weren’t going to games. Nobody had the money for tickets. They wanted autographs, and simply to hobnob with their sports heroes, to tell them “good luck today,” and get a thank-you in return.

“The majority of guys were great,” Lopez said. “We had no bad experiences with any player. Rickey was tough, but even he was not bad.”

And one of the sunniest A’s was Jose Canseco, the budding Cuban-born superstar with the bodybuilder’s biceps. He recognized the Lopez brothers early on and usually had a kind word. Carlos admired Canseco’s style.

“He had that flashy car, the red Jag, and he had Ms. Miami with him,” Lopez said. “It added to his character, you might say.”

When the A’s traded Canseco to Texas in 1992, “that was a pretty sad day for me,” Lopez said.

Canseco returned to Oakland for the 1997 season, but Lopez was in his 20s by then. He wasn’t sneaking through that hole in the fence anymore. He never lost affinity for the Bash Brother, though.

In 2010, when Canseco had begun his minor-league odyssey and was playing for the Laredo Broncos, Lopez sent an email to the general manager there, Jose Melendez, asking for a Canseco game jersey. Melendez is now Canseco’s agent.

“I was hoping he’d remember me, and he did,” Lopez said. “(Canseco) signed it for me. It was a big deal.”

The next year, Canseco was with the Yuma Scorpions, and Lopez drove to Chico to see him play. Saw him hit a grand slam, in fact.

“If you search ‘Jose Canseco grand slam’ on YouTube, you’ll see the video,” Lopez said. “It’s the one where he’s wearing a burgundy jersey. You can see my big old head there after he hits the home run.”

Lopez kept in touch, and the two men – former American League MVP and wide-eyed teenager – struck up a friendship. Now when Canseco’s in Northern California, they hang out. On the retired slugger’s recent trip, they went to a casino together. Lopez has set up private autograph-signing sessions for Canseco in his home.

Lopez sees a side of the outrageous athlete than most others don’t. He calls Canseco “pretty funny” and “pretty mellow.”

“He’s a really nice guy once you get to know him,” Lopez said. “You’ve got to break that wall a little bit, because so many have done wrong to him. And obviously he’s not a perfect person. But at the same time, he’s a human being.”

When Lopez was diagnosed with diabetes, he mentioned it to Canseco, and the famous man responded with great concern, urging Lopez to call him if he needed anything.

Recently, Lopez has assumed a vital niche in the Canseco universe: home run derby pitcher.

Lopez played catcher at Patten University in Oakland. The school dropped the baseball program after a year, and Lopez got hurt and didn’t play much longer, but he honed that 60-foot, 6-inch soft toss that makes catchers great batting-practice pitchers. He can groove a ball – most of the time.

“I haven’t perfected it yet,” Lopez said. “Believe me, Jose lets me know sometimes.”

Lopez pitched to Canseco for the derby in Sonoma, where I saw them a couple weeks ago, and then later in Pittsburg. Previously he had done it in Bakersfield.

For Lopez these are opportunities to stay connected to the guy who used to squeal his expensive tires in the Coliseum parking lot. And for Canseco they are – what? A chance to stay in the public eye as he considers his next move? A way to remain immersed in the game he still loves? A revenue stream?

No one really knows but Canseco. It’s safe to say that after blowing the lid off of the Steroid Era in his two books, “Juice” and “Vindicated,” Major League Baseball has not welcomed him with open arms. Lopez understands that, and he chooses not to judge Mr. 40/40.

“It comes down to money,” Lopez said. “When you’re making all this money because you’re putting home runs in the seats, you’re gonna do what you’re gonna do. And he made that mistake. But I treat him by my experiences only – good, bad or the ugly. I treat him the same. I wouldn’t have did that. But that’s what he decided. He lives with it, not me.”