SEATTLE (AP) — Seattle Mariners outfielder Victor Robles will miss at least 12 weeks after dislocating his left shoulder while catching a foul ball over the weekend, general manager Justin Hollander said Tuesday.

Robles, who was batting .273 with three doubles as the Mariners’ leadoff man, was placed on the 10-day injured list Monday.

Imaging revealed the dislocation caused a small fracture in a bone in the shoulder, and Hollander said it appeared the injury would heal without surgery. If no surgery is required, the fracture should heal in about six weeks, and then another six weeks of rehabilitation would be necessary.

The Mariners were playing at San Francisco on Sunday when Robles made a long dash to chase down a fly ball. The right fielder went over the low railing in foul territory to make the catch, fell over the wall and crashed into the netting in the process. Robles appeared to be in immediate pain, flipping the ball away with his right hand and grabbing at his left arm.

The 27-year-old Robles has played in 87 games with the Mariners since he signed as a free agent in June after the Washington Nationals released him. Since then, he’s batting .319 with 44 runs, 23 doubles, four homers, 29 RBIs and 16 walks and is 33 for 34 on stolen-base attempts.