The former All-Star and Gold Glove-winning third baseman was brought in as a guest of manager Mike Redmond, his close friend.
A few months ago, Redmond reached out to Lowell to see if he would spend a few days interacting with Miami's young players.
Lowell, who retired after the 2010 season, is a Miami native who still roots for the Marlins.
"I like being on the field," said Lowell, who a few days ago was a guest instructor with the Red Sox.
The past two years, Lowell visited Redmond when he was managing Class A ball in the Blue Jays' system.
"I think it's much better visiting him on the big league field," Lowell said. "For him, I'm excited."
Although the Marlins lost 8-2 to the Cardinals on Thursday, Lowell envisions the youthful Marlins will be much better than skeptics think.
"I think there is a lot more talent than people think on this team," Lowell said. "Now, how that translates, how soon? We'll see. I think the stereotype that there is no chance of winning here, I don't think that's the case."
Why the optimism?
"They are not major signs, but I think there is a carryover effect when you see Juan Pierre and [Placido] Polanco give quality at-bats," Lowell said. "Young guys see that. I look at that, kind of like how I felt in my first big league camp with the Yankees. I feel like I was kind of spoiled because in that lineup, eight out of nine guys grinded out at-bats and gave quality at-bats. You learn what they do, and you ask questions. It becomes, hopefully, an approach you can adopt. I don't think that means you go up to the plate taking pitches, but you kind of understand counts."
Lowell stays involved in the game as an analyst for MLB Network.
Like everyone else who resides in South Florida, he has an opinion on the controversial, 12-player trade the Marlins made with the Blue Jays on Nov. 19.
"My biggest argument would be," Lowell said, "I understand that the team lost a lot of games, but I think it would be hard to say they lost a lot of games because of Jose Reyes, Mark Buehrle and Josh Johnson. Like, that's not the reason the team lost. If you look at the team in April and May, it definitely was not the team that lost in August and September."