Pressly (back) threw a bullpen session at Minute Maid Park on Wednesday, Chandler Rome of The Athletic reports.
Pressly landed on the injured list over the weekend with a lower-back strain but is already moving through a throwing program. Astros manager Joe Espada said that Pressly probably won't require a rehab assignment, so the reliever would seem to have a shot to be ready for activation from the 15-day injured list Aug. 29 when he's first eligible.