The Astros optioned King to Triple-A Sugar Land on Friday, Chandler Rome of The Athletic reports.
King has appeared in 51 games out of Houston's bullpen this season, posting a 4.75 ERA, 1.43 WHIP and 44:19 K:BB across 53 innings. He was shelled for five runs on five hits with one strikeout across 1.1 innings during Thursday's 18-3 loss to the Angels. After throwing 37 pitches in that outing, he's heading down so the Astros can recall a fresher arm.