He hit the wall at full speed attempting to catch Ian Kinsler's third-inning RBI triple. He was holding his left arm and flexing his right knee after the play.
Jackson was checked by a trainer and manager Terry Francona, but stayed in the game. He was replaced by Darnell McDonald when the Red Sox took the field in the fourth.
Boston announced he had a bruised right knee.
Jackson was making his first start in right since being acquired from Oakland on August 31 for a minor-league pitcher and cash. He bounced into a double play in his only at-bat.