An ambulance carted Rock Cats centerfielder Byron Buxton off the field after he collided with rightfielder Mike Kvasnicka during a Wednesday night game against the Bowie Baysox at New Britain Stadium in Connecticut.
The players slammed into each another while chasing a ball into centerfield. Both men were down for a period of time after the collision.
Team officials say Buxton, the top prospect for the Minnesota Twins, suffered a concussion and was unconscious for 10 minutes after the impact.
Wednesday was his AA debut with the New Britain Rock Cats. Team General Manager Terry Ryan, who was there to see it unfold, said Buxton will be out for seven days. It's unlikely he'll play again this season, which ends in just a couple weeks.
"This was so unfortunate for him to have that collision," said Anne Provera, of West Hartford, who was in the stands. "I cried, I felt so bad. It's very sad."
MLB.com reports that Buxton was alert and talking as he was loaded into an ambulance.
Ryan said Kvasnicka is being treated for a left hip injury. Both players were taken to a local hospital.