Injuries are accumulating for the Houston Astros, with a key member of the pitching staff set to be out indefinitely. RHP Ryan Pressly is the latest to hit the 15-day injured list because of a lower back injury. It's unclear how the injury occurred. However, manager Joe Espada sounded relatively optimistic when speaking of Pressly to the press on Friday, via Astros' beat reporter Brian McTaggart.

“[Pressly has a] lower back strain. I don't think it's serious. He tried to pitch through it. It started in Boston (Friday, August 9). I don't think it's something serious. We decided to give him some time to heal before getting him back out there.”

The Astros are still rehabbing Justin Verlander after his injury stint. No firm date has been set for his return.

Houston is missing Cristian Javier, Jose Urquidy, Lance McCullers Jr. and Luis Garcia from their rotation, as all are on the 60-day IL. Only Garcia has an outside shot to return this season. From the bullpen, Bennett Sousa, Kendall Graveman, Oliver Ortega and Penn Murfee are also on the 60-day IL. Of that group, Murfee is the only one with a real opportunity to pitch this year.

The Astros have had spot injuries to key hitters like Alex Bregman with day-to-day elbow issues or Jose Altuve who missed a handful of games in July. RF Kyle Tucker took batting practice for the first time on Saturday and won't be available until he makes a rehab assignment, which has yet to occur.

How the Astros maximize bullpen, proceed without Ryan Pressly

Houston Astros relief pitcher Ryan Pressly (55) in action during the game between the Texas Rangers and the Houston Astros at Globe Life Field.
Jerome Miron-USA TODAY Sports

Having Verlander back soon will relieve some pressure on Joe Espada and the Astros. But the American League looks deeper and more talented than when Houston made postseason runs in years past.

Relief arms like Bryan Abreu, Josh Hader and Kaleb Ort must continue to lead the bullpen in Pressly's absence. The team recalled RHP Seth Martinez from Triple-A Sugar Land who's been bouncing between the minors and the 26-man roster for most of the season. He's made 41 appearances this year, pitching for 49.1 IP with a 2.92 ERA and 1.22 WHIP.

Pressly, 35, was the team's closer last year but lost that role with Hader's arrival. The righty made five appearances in August across five innings. In that span, he allowed eight hits, four earned runs and three walks. Considering how Espada described Pressly's injury, it's been lingering, and the team decided it'd be best to rest him ahead of the playoffs. Martinez's recall gives them a capable arm until Pressly is ready to return.