ST. LOUIS (CBSMiami) – News out of Saturday’s Miami Marlins vs. St. Louis Cardinals game doesn’t sound promising for Marlins star Giancarlo Stanton’s All-Star prospects.

Stanton was taken out of Saturday’s game in the third inning due to right knee discomfort, according to CBS4 news partner the Miami Herald. Before leaving the game, Stanton hit single in the second inning and scored on Justin Ruggiano’s home run without showing signs of discomfort.

Stanton’s knee has become problematic over the last few weeks. He’s set to play in next week’s All-Star Game and take part in the Home Run Derby. However, the team said it wanted him to play both weekend games against the Cardinals before clearing him to play in the All-Star Game.

The slugger was only a pinch hitter in Friday’s game against the Cardinals. Stanton told reporters Friday that he will eventually have to have surgery to remove some loose bodies from his knee, according to the Herald.