Boston Red Sox first baseman Triston Casas left Friday night’s game against the Minnesota Twins on a stretcher due to a serious left knee injury.

Casas beat out a check-swing tapper that Twins pitcher Joe Ryan misplayed for an error in the bottom of the second inning. After stepping hard on top of the first base bag, his left foot hit the foot of Minnesota first baseman Ty France and he fell hard on his left knee. Casas stayed down before being attended to by a trainer.

Boston manager Alex Cora said after the team’s 6-1 victory that Casas was being evaluated.

“He has a significant knee injury,” Cora said. “He’s at the hospital right now, getting more tests. We’ll have more information tomorrow.”

Cora said Casas didn’t fully understand what had happened as he was worked on by trainers.

“It seems like he was in shock, to be honest to you,” Cora said. “He said right away that he didn’t feel it. It’s tough. He works so hard and we want him on the field. That was a hustle play, too, and that happened.”

Casas was replaced by Romy Gonzalez at first base.

Casas, 25, is batting .182 with three homers and 11 RBIs in 29 games this season.

Casas also ran into misfortune last season, when he was limited to 63 games due to a left rib cage injury. He batted .241 with 13 homers and 32 RBIs.

–Field Level Media