Polanco was hoping to return on Wednesday from back spasms he first experienced on Saturday. The 37-year-old took batting practice and he took ground balls at third base.
"He did everything," manager Mike Redmond said. "He just made a couple of throws, and he feels it."
Matt Downs, who is competing for a utility spot, got the start at third in place of Polanco.
Redmond is hoping Polanco will need only a few more days to recover.
"If he needs two more days or three more days, whatever it is," Redmond said. "We will see how it progresses. He knows his body, and he knows what it will take for him to be ready."
Polanco's health is of concern.
A year ago with the Phillies, Polanco appeared in 90 games. He missed time with lower back inflammation.
With three weeks before Opening Day, the Marlins are confident Polanco will have plenty of time to get ready for the season.
With him out, it gives the team more chances to look at players like Downs, who has impressed with his versatility.
"He's the ultimate utility guy," Redmond said of Downs. "He told me he can also catch."
Downs plays all the infield positions, and he can be a candidate to be a third-string, emergency catcher.
Joe Frisaro is a reporter for MLB.com. He writes a blog, called The Fish Pond. Follow him on Twitter @JoeFrisaro. This story was not subject to the approval of Major League Baseball or its clubs.