Stanton ran, threw and fielded fly balls in the outfield at Busch Stadium. He ran the bases, and was able to tolerate some discomfort. He also hit in the batting cages.
The slugger then made a pinch-hit appearance in the ninth inning of the Marlins' 3-2 win over the Cardinals, striking out.
After Stanton logged about 40 minutes of activity before the game, Marlins manager Ozzie Guillen said he expects to have him in the lineup on Saturday and Sunday against the Cardinals.
Barring any setbacks, Stanton anticipates participating in the State Farm Home Run Derby on Monday night on ESPN at 8 ET at Kauffman Stadium in Kansas City, and the All-Star Game on Tuesday.
Although the slugger is being given the green light to return to the lineup, the fact remains his knee at some point will require surgery. That remains a concern that will hover over the team until the procedure is performed.
Recovery from surgery, Stanton said, could be two to eight weeks. As long as the Marlins are in playoff contention, the right fielder will try to play through the discomfort.
"It's a big gap, but it all depends on the reaction to it," he said of surgery recovery time. "It just depends. I didn't have a lot of swelling or bruising. So that means it would be however my knee reacts to being cut open."
An MRI on Tuesday revealed Stanton has "loose bodies" -- cartilage or bone fragments -- in the knee. The 22-year-old said he felt the pieces moving as he was running.
"Just weird," Stanton said of the sensation. "It wasn't restricting, but it was a weird feeling with it bouncing around in there. But, I'll play [Saturday]."
Stanton felt his right knee lock up during Monday's game at Milwaukee, and he hasn't played since, missing four straight starts.
Coming out of Spring Training, the Marlins were concerned about Stanton and left fielder Logan Morrison (right knee). Like Stanton of late, Morrison's knee resulted in him getting occasional days off.
"This to roll the dice, you don't know what's going to happen," Guillen said.
Guillen added that he hopes Stanton is working hard to get on the field to help the Marlins, and not just to take part in the All-Star festivities.
"I just want him to be ready for us, not the National League," the manager said. "He's 22 years old. If that kid was 18 or was my son, then I'd make the decision. I don't make the decision for grown kids. Maybe the front office will.
"For me, we're going to play next Friday with or without him. That's the bottom line. He's going to be in the lineup or not, but the Marlins are going to play. I'd like to see him in the Home Run Derby, because he'd be representing the Marlins. I want him in that. That's up to him."
Looking at the big picture, the Marlins may find themselves playing Stanton on a limited basis, perhaps four or five days a week. That could be the best-case scenario until a procedure is performed.
"We've been lucky since we left Spring Training that this guy has done what he has done, because we thought it could be a little crazy," Guillen said. "We have to monitor. If we have to play him, three times, four times a week, and treat him the same way we treat LoMo, I don't mind that. I'd rather have him four times, five times a week than nothing."
Stanton is one of the rising power threats in the game, batting .283 with 19 home runs and 50 RBIs. He was named NL Player of the Month in May.
He plans on playing as long as the knee doesn't result in him suffering more damage.
"I've got to read my body," Stanton said. "If I'm changing the way I run or hit or anything, then that is going to lead to other problems and change the way I play on the field."
Basically, as long as the Marlins are in the race, and he doesn't feel he will create any further damage, he will hold off on a procedure.
"I've had knee problems before, so I'm not new to the fact of managing it," Stanton said. "It's just new to this feeling. I know my body well. So, it's just a matter of what's it going to do, and tell me."