The Astros recalled Walter from Triple-A Sugar Land to start Sunday's game against the Guardians, Brian McTaggart of MLB.com reports.

EDGE Analysis

The left-hander is joining the Astros to start Sunday and give Lance McCullers some extra rest between outings. Walter made his season debut for the Astros on May 20 in Tampa Bay and covered five scoreless frames, and he's enjoyed a dominant campaign at Sugar Land with a 2.08 ERA, 0.76 WHIP and 49:7 K:BB across 47.2 innings.

Walter will start Sunday against the Guardians, Brian McTaggart of MLB.com reports.

EDGE Analysis

Walter joined the Astros as part of the taxi squad, hinting at the potential for him to start Sunday. That is now confirmed, though a formal roster move will come later Saturday or Sunday. Walter made a spot start with the Astros on May 20 and delivered five shutout innings with a 5:1 K:BB against Tampa Bay.

Walter is in Cleveland on Saturday and will be part of the Astros' taxi squad Matt Kawahara of the Houston Chronicle reports.

EDGE Analysis

Walter's presence indicates that the 28-year-old southpaw could start in Sunday's series finale against the Guardians, per Kawahara. Walter has a 3-1 record across 11 games (seven starts) with Triple-A Sugar Land this season and holds a 2.08 ERA, 0.76 WHIP and 49:7 K:BB across 47.2 innings. He made a spot start for Houston against Tampa Bay on May 20, during which he allowed three hits and one walk while striking out five across five scoreless innings while not factoring into the decision.

The Astros optioned Walter to Triple-A Sugar Land on Wednesday, Matt Kawahara of the Houston Chronicle reports.

EDGE Analysis

Walters spun five scoreless frames and struck out five in a start Tuesday versus the Rays, but he nonetheless finds himself back in the minors a day later. The left-hander has likely earned future starts at some point later this season.

Walter did not factor into the decision against the Rays on Tuesday, allowing three hits and one walk while striking out five across five scoreless innings.

EDGE Analysis

Walter was called up from Triple-A ahead of Tuesday's start after posting a 2.27 ERA, 0.71 WHIP and 34:7 K:BB across 35.2 innings with Sugar Land. He faced four batters or fewer in all five innings he pitched and was in position for the win, but he came away with the no-decision after the Rays scored two runs in the eighth inning. It was the first major-league start of Walter's career, and he'll likely be in the Astros' rotation for as long as Spencer Arrighetti (thumb) is on the injured list. Walter's next start is tentatively slated for this weekend at home against the Mariners.

The Astros selected Walter's contract from Triple-A Sugar Land on Tuesday, Chandler Rome of The Athletic reports.

EDGE Analysis

Walter will start Tuesday's contest at Tampa Bay. The left-hander has posted a 2.27 ERA and 34:7 K:BB over 35.2 innings with Sugar Land this season. With Hayden Wesneski (elbow) out for the season and Spencer Arrighetti (thumb) not close to returning, Walter will have a chance to stake his claim to a rotation spot in Houston.

Walter will start Tuesday's game against the Rays, Matt Kawahara of the Houston Chronicle reports.

EDGE Analysis

Walter was rumored to be in the mix for a promotion, and the team has since confirmed his status as Tuesday's starting pitcher. It remains to be seen whether the 28-year-old will be able to stick around for another turn through the rotation given the number of injuries to the team's starting pitching staff.

The Astros added Walter to their taxi squad Monday and could call him from Triple-A Sugar Land to start Tuesday's game against the Rays in Tampa, Chandler Rome of The Athletic reports.

EDGE Analysis

Walter has been sharp with Sugar Land in 2025, posting a 2.27 ERA and 34:7 K:BB over 35.2 innings covering five starts and four relief appearances. The southpaw's lone previous big-league action came back in 2023, when he turned in a 6.26 ERA over nine relief appearances with the Red Sox. If Walter does in fact get called up to start Tuesday, he could be sent back down to Sugar Land after the game.

The Astros reassigned Walter to minor-league camp Thursday, Brian McTaggart of MLB.com reports.

EDGE Analysis

Walter previously saw big-league action out of the Boston bullpen in 2023, but he was released this past August after a left shoulder strain kept him from pitching throughout the 2024 season. He joined Houston on a minor-league deal shortly after his release from Boston and was cleared for spring training, but he fell short in his bid for a long-relief role with the big club after giving up four earned runs on nine hits and three walks over seven innings across his four Grapefruit League outings. Walter will likely open the season at Triple-A Sugar Land, and he could be a candidate to work out of the rotation.

Walter (shoulder) allowed one run on two hits and a walk while striking out one batter over one inning in Saturday's 6-3 loss to the Nationals in Grapefruit League action.

EDGE Analysis

Walter missed the entirety of the 2024 season while nursing a right shoulder strain, but he's now all set for the 2025 campaign. The left-hander last pitched in 2023, producing a 6.26 ERA and 1.70 WHIP with 16 strikeouts over 23.0 innings in nine appearances with the Red Sox. Walter is participating in spring training as a non-roster invitee and if he sticks around with the Astros, he'll likely begin the year with Triple-A Sugar Land.