Spencer Arrighetti’s Incredible Start Puts Him Among Former Astros Stars

The Houston Astros should be thankful that Spencer Arrighetti has reclaimed the form that made him such a promising pitcher in 2024.

Houston Astros starting pitcher Spencer Arrighetti. | Kamil Krzaczynski-Imagn Images

Spencer Arrighetti can only pitch every fifth game. But for a beleaguered Houston Astros rotation, that every fifth game is like music.

Arrighetti took the ball on Friday in Chicago when the Astros faced the Cubs. He threw five innings but allowed just two hits and struck out five. If not for the four walks, he likely would have gone an inning longer.

But it was enough to set up the Astros bullpen. It was Houston’s first win at Wrigley Field in 13 years.

Houston has won five of its last nine games and Arrighetti has done something that only a handful of Astros pitchers have ever done.

Spencer Arrighetti’s Place in Astros History

Spencer Arrighetti's 1.32 ERA is the ninth-lowest in Astros history after a pitcher's first seven starts of a season. Here are the eight lower ones, according to @Stathead pic.twitter.com/oUlps8Fzj3

— Chandler Rome (@Chandler_Rome) May 22, 2026

Arrighetti wasn’t in the opening day rotation and was promoted in early April after a spate of injuries to the rotation. He has now started seven games and is 6-1 with a 1.32 ERA. That ERA is the piece that’s critical to the club he’s joined.

Per Chandler Rome of The Athletic on X (formerly Twitter), Arrighetti’s is the ninth-lowest ERA of any Astros pitcher in their first seven starts in a season in franchise history according to data gathered at Stathead. The list includes some of the best pitchers in franchise history, such as Roger Clemens, Nolan Ryan and Justin Verlander.

But the best ERA — in fact the two best ERAs in that span — belong to Bob Knepper.

The rock-solid 1980s starter finished his first seven starts with a 0.89 ERA in 1988. He’s the only pitcher in the group to finish that span with a sub-1.00 ERA. When he did that, he broke his own record for the lowest ERA through seven starts in 1981, which was 1.03.

Incredibly, Knepper set the mark four days before Ryan approached it. The pair were in the same rotation that season and Ryan posted a 1.12 ERA in his first seven starts four days after Knepper set his mark.

After Knepper, the list included Mike Cuellar (1.05, 1966), Clemens (1.10, 2005), Ryan (1.12), Verlander (1.13, 2018), Randy Johnson (1.17, 198) and Danny Darwin (1.30, 1990).

Arrighetti made his MLB debut in 2024 and went 7-13 with a 4.53 ERA in 29 games (28 starts) with 171 strikeouts and 65 walks in 145 innings. He followed that by making the opening day rotation for 2025 but was quickly moved to the IL after he suffered a broken right thumb during batting practice. He returned but ended up going 1-5 with a 5.35 ERA with 31 strikeouts and 20 walks in 35 innings.