While the majority of the Houston Astros' starting rotation flounders, Spencer Arrighetti is thriving.Thanks to a spectacular May that saw him allow just three earned runs over the course of 29 innings, Arrighetti was named the American League Pitcher of the Month. There's no question that he's been the standout star of the rotation for Houston so far this season, and this past month of excellent performances solidified him as one of the most exceptional arms in all of baseball.It's been said before, and it'll be said again about a variety of different Astros players, but if the team is going to have any sort of success in 2026, then Arrighetti will need to continue to light up the box score day in and day out.A Month of Dominance on the MoundYour AL and NL Pitchers of the Month for May:Spencer Arrighetti: 4-1, 0.93 ERA, 29 IP, 22 KsCristopher Sánchez: 4-0, 0.00 ERA, 39 IP, 45 Ks pic.twitter.com/PUDJkdlPMi— MLB (@MLB) June 3, 2026Arrighetti made five starts in May, with each seemingly getting even more impressive.On May 2, against the Boston Red Sox at Fenway Park, Arrighetti unfurled five innings of masterful pitching, allowing just one run on five hits. He struck out four and walked five. Seven days later, he was arguably even more impressive against the Cincinnati Reds. He did allow three runs, but only one of those was earned. Five Reds went down on strikes, while three reached base via walks.If there's one blemish on Arrighetti's May, it's that he did have a propensity to allow a fair amount of free passes. Yet he was still able to keep opponents off the scoreboard despite all the walks, which, in the end, is all that matters.Arrighetti had his best game of the month on May 15 against the Texas Rangers. It was there that he threw 7 1/3 innings of shutout baseball, striking out five and walking four. He allowed just one hit.Spencer Arrighetti is the American League Pitcher of the Month for May.Well deserved. 4–1 record3 ER in 29 innings.165 batting average against.Arrighetti would be the AL’s ERA leader if he had enough innings to qualify. pic.twitter.com/0KO8axaJWM— Michael Shapiro (@mshap2) June 3, 2026He pitched another shutout, this time versus the Chicago Cubs on May 22, but was only able to go five innings thanks to an elevated pitch count. Still, the lack of base hits allowed — he gave up just two — was mighty impressive and showed just how magnificent his stuff is at the moment.The final outing of the month came on May 28 against the Rangers. While he wasn't able to match his previous performance on May 15, he did allow just one run on three hits while limiting the number of walks to just one — a low for the month. Three Rangers went down on strikes.Arrighetti Emerging as Houston's AceHouston Astros pitcher Spencer Arrighetti. | Troy Taormina-Imagn ImagesThe name of the game is run prevention, and Arrighetti is doing that to perfection. His 1.34 ERA is the second-lowest in MLB behind only Shohei Ohtani's 0.82 (minimum 45 innings pitched). In many ways, that's more impressive than being named AL Pitcher of the Month.Heading into the season, few people would've been able to peg Arrighetti as the Astros' No. 1 arm. With Hunter Brown leading the rotation, there was little room for pitchers like Arrighetti to enter that conversation. But once Brown went down with an injury, the door was open for anybody to walk through.In the end, it was Arrighetti who took advantage of the opportunity, and the Astros are better off for it.Add us as a preferred source on GoogleFollow