Manager Joe Maddon said it was likely that Ohtani would be back in the designated hitter spot for Saturday night's game.
The Japanese two-way sensation said after Thursday night's 6-3 loss that he felt a twinge in his back after throwing a pitch during the first inning. Trainers started working on him after the third inning, when they noticed Ohtani was stretching differently on the mound between pitches.
Ohtani pitched six innings and allowed five runs on six hits with 10 strikeouts. The right-hander is 3-3 with a 3.45 ERA. He entered Friday sixth in the American League in strikeouts with 63. He is batting .249 and is tied for sixth in the AL with 29 RBI.
Rendon had an MRI on his right wrist Friday. It is something he has been dealing with for most of the season, but it flared up during Thursday's game when he tried to swing on a ball outside the strike zone. He played in only 58 games last season due to various injuries.
Tyler Wade was in the lineup at third base in Rendon's absence.
The Associated Press contributed to this report.