Stanton went 0 for 2 in his first game since being hit in the face by Mike Fiers' fastball in September.
''I felt good in the box,'' Stanton said. ''We're right on track. It was good to be in a game setting again.''
Stanton had a fly out to left in the first inning against Carlos Martinez. Three innings later, he flew out to right.
Stanton said that too much was being made of his comeback from the injury. He was wondering when everyone will stop asking him about how he feels.
''I guess I've got to get a hit first,'' Stanton said.
Martinez retired all six batters he faced, striking out three.
Martinez said through a translator that the Cardinals thought Stanton might be tentative in his first at-bat, so they tried to pitch him away, hoping Stanton's bat couldn't catch up.
Martinez's fastball regularly clocks in the high 90 mph range.
''It's good for a spring training at-bat - to get your timing to 95-plus (fastball) is always good,'' Stanton said.
That first at-bat also marked the game debut of Stanton's new batting helmet, which features a football facemask-like guard that protects his left cheek and jaw.
Stanton played a role in designing the guard and said it didn't bother him during Thursday's at-bats.
''That's what I went to the lab for - to make sure I got it right so I wouldn't have to be getting a feel for it out there,'' Stanton said.
Fiers' fastball broke Stanton's orbital bone and damaged five teeth, ending the slugger's 2014 season.
The Marlins expected Stanton to make a full recovery and signed him to a 13-year, $325 million contract during the offseason.
After Thursday's game, Marlins manager Mike Redmond said he wasn't nervous about how Stanton would react the first time the slugger stepped in the batter's box.
''He looked great,'' Redmond said. ''His at-bats were good. His takes were good. His pitch selection was good. He looked fine.''