Rowand, who broke in with the White Sox in 2001, will weigh retirement if another big league opportunity isn't available.
"I hope not," Marlins manager Ozzie Guillen said. "I think he's healthy. He can still play. I think the guys around him were better than him. It was very hard. I felt when we brought him here, I was pretty sure he'd make the club. But it's not what we say, it's what we see. I think he can still play."
Also on Thursday, outfielder Bryan Petersen was optioned to Triple-A New Orleans, clearing the path for Chris Coghlan to make the club.
The team also re-assigned right-hander J.D. Martin and infielder Nick Green -- both non-roster invitees -- to Minor League camp.
Rowand initially was in the lineup on Thursday to play center field against the Cardinals, but he was scratched shortly before the game started. Once the decision to release Rowand was made, the Marlins replaced him in center field with their top prospect, Christian Yelich, who is not in big league camp.
Yelich, 20, will open the season at Class A Jupiter.
Rowand previously played for Guillen while with the White Sox. But throughout the spring, Guillen repeatedly noted that he didn't believe in track records, and that the team would keep the players it felt would provide the best chance to win.
"The thing is, there were better guys than him in Spring Training," Guillen said. "During the season, maybe not. But in Spring Training, a lot of guys played better than him."
Kearns, meanwhile, has been one of the most productive Marlins in camp. He's hitting .316 with three home runs and nine RBIs.
Kearns can play first base and both corner outfield spots.
"Kearns came out of the gate swinging the bat better," Guillen said. "He can play a bit everywhere. [Rowand] just got beat for the job."
The Marlins are still weighing whether to keep non-roster invitee infielder Donovan Solano, who has impressed Guillen and the organization. Donnie Murphy is expected to be the backup infielder.
Before making Thursday's moves, the Marlins checked with both of their corner outfielders to get health updates.
Logan Morrison (right knee) and Giancarlo Stanton (left knee) each played seven innings in a Triple-A game on Thursday. The two are scheduled to play on Friday night, when the Marlins take on the Nationals in Viera.
The Marlins are now seeking to find out if both can be ready for Opening Day on Wednesday against the Cardinals at Marlins Park.
"With Morrison and Stanton, it was easy," Guillen said. "You're in or you're out. If you make the ballclub, great, awesome. If you don't make the ballclub, we have to go to Plan B. I saw them running early. They improved a lot."
Coghlan is expected to get playing time early in the season, because Stanton and Morrison will be monitored.
"He's healthy," Guillen said. "I think he's going to be playing a little bit more, because we need to give the corner guys a little bit of rest. I'm not going to platoon players, but I'm going to give them days off because of the problems [knee concerns] from last year."