Because of Polanco's versatility, he may also see some time at second base. But on the first day of full-squad workouts, the Marlins are primarily looking at him to lock down third base.
Polanco joins a young Miami squad after spending the past three seasons on the Phillies, who won two National League East titles in that span.
Going from an established club to a team with something to prove was actually an easy decision.
"I was a free agent. I live here in Miami," said Polanco, who signed for $2.75 million. "I was just waiting for calls to see what teams were interested. When the Marlins jumped in, it was a very easy decision."
Health will be key for the veteran, who missed time in 2012 due to lower-back issues. He played in 90 games, and batted .257 in 303 at-bats.
"I'm good. I'm 100 percent," Polanco said. "That's one thing I said to myself, 'If I'm not healthy, I'm not going to play.' I got the point where I'm healthy. I wanted to play, and I signed with the Marlins."
The Marlins are hoping veterans like Polanco mix in well with young, unproven players.
"I think it is important to have the right combination of young guys and veteran guys," he said. "I think we have that here."
As for low expectations, he added: "Nobody thought the Oakland A's were going to win it last year, and they won the [American League West] division. It's just one of those things. If you look around, we have a lot of talent and I think we can do it."