Baltimore Orioles first baseman Ryan Mountcastle was placed on the 10-day injured list Wednesday with inflammation in the acromioclavicular joint of his left shoulder.
Mountcastle, 26, last played on Sept. 13 when the team hosted the St. Louis Cardinals. He was removed from the game for what the Orioles originally described as "left shoulder soreness."
The first baseman was also placed on the injured list on June 13 with vertigo. He returned to the lineup nearly a month later on July 9.
Through 111 games played this season, Mountcastle has an overall batting average of .