Thaiss signed a minor-league contract with the Astros on July 24.
The Astros signed Velazquez to a major-league contract Monday, Matt Kawahara of the Houston Chronicle reports.
Delgado was optioned to Triple-A Sugar Land on Monday, Chandler Rome of The Athletic reports.
The Astros outrighted Velazquez to Triple-A Sugar Land on Sunday.
Altuve went 1-for-4 with a two-run homer and an additional RBI in Sunday's 7-6 loss to the A's.
Paredes went 1-for-3 with a home run, a walk and three RBI in Sunday's 7-6 loss to the Athletics.
Javier did not factor into the decision Sunday against the Athletics, allowing three runs on four hits and two walks while striking out a season-high eight over four innings.
Snell (2-1) earned the win Sunday, allowing two hits, three walks and a hit-by-pitch over six scoreless innings against the Pirates. He struck out six.
Manager Dave Roberts said Sunday that Lauer will be available out of the bullpen going forward, Fabian Ardaya of The Athletic reports.
Pages had a compression screw inserted into his fractured left hand Sunday in an attempt to expedite healing, Fabian Ardaya of The Athletic reports.
