The Astros activated Teng (knee) from the 15-day injured list Friday.
Teng had originally been optioned to Triple-A Sugar Land in late June, but the transaction was changed to a placement on the 15-day IL with a right knee sprain. Teng will rejoin Houston's bullpen after making 10 starts for the team. He has a 4.36 ERA, 1.36 WHIP and 63:28 K:BB across 64 innings spanning 23 appearances this season.