The Angels placed Rendon on the 10-day injured list Tuesday, retroactive to July 27, due to lower-back inflammation.
The 34-year-old sat out Saturday and Sunday, so the injury presumably flared up during or after Friday's matchup with the A's. Rendon returned from a nearly three-month absence due to a hamstring strain in early July, but he played in just 14 games before going back on the injured list. It's unclear how long Rendon is expected to be sidelined this time around, but he'll be eligible to be reinstated Aug. 6.