Stanton had two plate appearances in his first spring action since March 5, going 0-for-1 with a walk. The three-time All-Star also was caught stealing after drawing his second-inning walk against New York Mets ace Matt Harvey.
"I felt relatively good," Stanton told reporters. "I was just getting in the swing of things again. Any time you can get in there and work on that is good."
Stanton originally was listed as Miami's designated hitter, but the Marlins elected shortly before the first pitch to start him in right field.
"I wanted to get a quicker gauge [of how my knee would respond]," said Stanton, who played five innings in right field. "Just sitting around and [being the] DH is not a good gauge for the situation like that. If it was something else, DH would be ideal, but I wanted to be out there."
Marlins manager Don Mattingly said that Stanton was tested on Sunday. "He kind of did everything," Mattingly said. "Got on base, ran pretty much all directions. We'll find out how he does over the day off. Hopefully, he's good and we'll just go from there."
Stanton had arthroscopic surgery to remove bone chips in his right knee in 2012. He is confident that he will regain his timing at the plate, saying he doesn't expect his absence to jeopardize his availability for Opening Day.
"I'd say my timing for fastballs is good," Stanton said. "I've just got to stay back for the off-speed and fastballs away."
Said Mattingly, "The fact that he was able to do everything, he looked like he was running pretty good. If he can keep going, there's no question he'll be ready to go [Opening Day]."
Information from The Associated Press was used in this report.