Hours after he was taken off the field on a cart following a knee injury, Phillies first baseman Rhys Hoskins has been diagnosed with a torn ACL in his left knee, the team announced Thursday.

No timetable has been determined for his return, nor has his surgery date been set. The team said that the procedure would be “reconstructive.”

The injury occurred during a spring training game against the Tigers. Hoskins attempted to field a ground ball at first, but stepped awkwardly and fell to the ground, holding his knee in pain. He remained on the ground for several minutes while being tended to by trainers before being carted off the field.

Hoskins hit 30 home runs with 79 RBIs across 156 games last season, setting a career high with 145 hits. He played a key role in ending the Phillies’ 11-year postseason drought, helping to lead the team to the World Series.