The Victoria native will be re-examined Thursday and the team says Saunders is expected to miss "some time."
Saunders left Wednesday night's game against Houston in the first inning after running down a deep drive hit by leadoff batter Jose Altuve. Saunders chased the ball in a full sprint across the warning track and caught it just as he collided with the padded wall. He fell to the ground holding his right shoulder.
He stayed down for several minutes while the Seattle medical staff treated him. Saunders then walked to the dugout holding his right arm close to his ribs.
Jason Bay took over in right field. Saunders was batting .286 with a seven-game hitting streak.