The pitcher was Roger Clemens, who was putting the finishing touches on a Hall-of-Fame-type career the same time Maybin was completing his meteoric rise through the Tigers' Minor League system to the big leagues.
"That was an awesome feeling and it's something I'll always remember," Maybin said. "He was one of the best to stand on the mound ever. And to have success against a guy like that who is so good ... that's helped me remain confident in my ability."
The home run off Clemens on that day in August essentially remains a moment froze in time for Maybin. It remains the highlight of his young career, which certainly says a lot about where the Padres new center fielder has been these past four seasons.
Maybin's confidence, understandably, has wavered some since that day in New York, as he has not only bounced back and forth from the Minor Leagues to the Major Leagues -- but also bounced in and out of the lineup enough times to make his head spin.
"The past couple of years, it was a situation where I felt I was on a short leash. I think for any young guy coming up, you need those reps during times when you have success and when you're going poorly," Maybin said. "You need time to go through that.
"Coming over here [San Diego], it's like a ton of weight has been lifted off my shoulders. I don't have to look over my shoulder anymore."
No, that won't happen in San Diego, as Maybin is the Padres starting center fielder now and for the foreseeable future. He's the kind of athletic and toolsy player that the Padres new regime wants to draft and built around.
"His skill-set sets up very well for our style of play, our ballpark and our division," San Diego manager Bud Black said. "And in our park, right-handed pull power is a plus. And he's still young. Hopefully, it's his time to smooth some things out."
General manager Jed Hoyer thought enough of the former first-round Draft pick to send away relievers Ryan Webb and Edward Mujica to the Marlins to get Maybin, a player that the Marlins were unwilling to part with several times last season when the Padres called to inquire of his availability.
The Marlins, apparently, changed their tune on Maybin in the offseason, and the Padres -- looking for a player capable of covering ground in PETCO Park, which ranks as one of the biggest center fields in baseball, swooped in to grab him.
"We talked to a ton of people about Cameron and everyone had great things to say about him as a person. And everyone felt his development path impeded his progress as a player," Hoyer said.
"This is a 23-year-old guy and we have prospects in our organization that are older than Cameron. These are guys who are breaking into the big leagues or are still a year away."
But which Maybin will the Padres get?
Will it be the player who has the .306 batting average and .393 on-base percentage in 418 career Minor League games, or the one who has struggled in a Major League career with the Tigers and then the Marlins, hitting .246 with a 31 percent strikeout rate?
The Padres and, obviously, Maybin, think it will be the former, and that he'll be energized by a move to a team that fully intends to simply let him play.
"Man, I'm so eager right now," Maybin said. "To get the chance to go through and to be able to experience a full season, is great. I definitely believe in my abilities and with 500, 600 at-bats, I feel that I can do some things to help this ballclub meets it goal.
"And with that opportunity, I think I can do some special things to help this team win."
For the longest time, Maybin figured that his best opportunity would come with the Tigers -- the team that used the 10th overall pick in the 2005 First-Year Player Draft to sign him out of Roberson High in Asheville, N.C.
Maybin bolted through the Tigers system, hitting .304 in his pro debut in the summer of 2006. A year later, he hit .304 for Class A Lakeland before earning a brief promotion to Double-A Erie.
Maybin didn't stay in Erie long, hitting four home runs in his first 20 at-bats, and thus impressing Tigers scout Mike Russell to the point where he filed a glowing report that then-manager Jim Leyland -- who reportedly was enamored with Maybin's speed and raw, athletic ability -- saw.
Not long thereafter, Maybin was on his way to New York for his debut with the Tigers, who were in the thick of a playoff chase in the American League Central Division.
Maybin hit .143 with 21 strikeouts in 49 at-bats and had one hit in 19 at-bats during the month of September. The Tigers won 88 games and finished in second place in the AL Central. He was traded to the Marlins in the offseason that year, part of an eight-player deal that saw the Marlins ship Miguel Cabrera to Detroit.
Maybin doesn't think he was rushed to the Major Leagues, though others in the game feel that it stunted his growth as a player.
"I'm always up for a challenge and I think that it was a great experience for me. I'm very grateful for that experience," Maybin said. "It was a good part of my maturation process, as far as having to handle the ups and downs at a young age. It taught me to stay humble and keep working.
"I think it was deserved, and I think they [Tigers] felt the same thing. I think they saw something in me. I don't think it was too soon."
Maybin spent nearly all of 2008 in the Minor Leagues and hit .250 in 176 at-bats with Florida the following year. He was the Marlins Opening Day center fielder a year ago, but was sent to Triple-A on June 17 after hitting .225 in 182 at-bats.
Maybin isn't one for excuses and he doesn't dismiss his struggles with the Marlins, but at the same time he had a sneaking suspicion that his next 0-fer would lead him back to a seat on the bench.
"It's tough when every time you go out, if you don't have a good night, they are going to come grab you at any moment," Maybin said. "That's not a way to play this game. It's tough enough as it is, but when you're worrying about things you can't control, it's even harder."
Now with the Padres, Maybin has been embraced by the organization, manager, coaches and his new teammates. He had a single and stole a base in Sunday's game with Seattle and roamed center field with ease.
Maybin was standing in front of his locker last week, smiling. He looks and sounds like he's at peace with his past, his surroundings and, for maybe the first time, his future.
"I'm only 23 and I would probably just be coming out of college right now. It's been a great process so far and I've learned a lot. I'm excited. And when you look at it, this is going to be my first full season. I'm still pretty young."