The Astros' waiver-wire flier on Nelson Velázquez didn't last two full weeks. Houston claimed the outfielder off waivers from the Cardinals on August 10, and by August 20 he was already designated for assignment, one of the shortest stints imaginable for a player who was supposed to add outfield depth for the stretch run.
It wasn't performance that sank him, though the numbers didn't help his case. Velázquez went hitless in five plate appearances across 3 games with Houston, unable to find any traction before the roster crunch hit. In St. Louis earlier this season he hit.205/.273/.410, with some sneaky pop against lefties, 4 homers in that split, which is presumably what made him worth a claim in the first place.
The real driver here is Jeremy Peña. Houston's shortstop took a 100 mph sinker off his right hand from Angels reliever Walbert Ureña, got pulled for a pinch hitter, and needed both X-rays and an MRI to make sure nothing structural was broken. Imaging came back clean, but Peña is reportedly still sore, and the Astros weren't taking chances with their middle infield depth in the middle of a pennant race.
To open a 40-man spot for infielder Raynel Delgado, who got the call from Triple-A Sugar Land to cover for Peña, Houston needed to shed a body. Velázquez was out of minor league options, which made him the easiest man to cut loose instead of Shay Whitcomb, who'd actually been DFA'd to make room for Velázquez in the first place just 10 days earlier.
That's the kind of roster chaos that happens in August when injuries pile up and waiver-claim reinforcements don't pan out fast enough. Velázquez now has the option to elect free agency if he clears waivers again, since the trade deadline has already passed and Houston can't just stash him in the minors.
For the Astros, the more important storyline is whether Peña avoids the injured list altogether. Losing a waiver claim who went 0-for-5 barely moves the needle, but losing their starting shortstop for any real stretch would be a much bigger problem heading into September.