Houston Astros Add Reliever From Miami Marlins in Post-Trade Deadline Move

John Rooney is set to make his MLB debut after getting poached off the Miami Marlins' Triple-A roster by the Houston Astros in a late-breaking move Sunday.

Jupiter, Florida, USA; Miami Marlins pitcher John Rooney (79) pitches in the sixth inning against the St. Louis Cardinals at Roger Dean Chevrolet Stadium. | Jim Rassol-Imagn Images

The Miami Marlins have traded left-handed pitcher John Rooney to the Houston Astros in exchange for cash considerations, the clubs announced Sunday morning.

The deal came across the wire nearly three days after the trade deadline passed. However, since Rooney was not on the Marlins' 40-man roster, he was still eligible to get moved.

While Miami didn't have Rooney pitching in the big leagues, Houston is giving him a shot right out of the gates. The lefty reliever is set to join the Astros for their series finale against the Boston Red Sox at Fenway Park on Sunday, wearing jersey No. 67 for his MLB debut.

Houston optioned right-handed pitcher Luis Contreras to Triple-A Sugar Land to make room for Rooney. Contreras, who last pitched Wednesday, owns a 6.75 ERA, 1.583 WHIP and -0.2 WAR in nine appearances with the Astros this season, not including his 1-2 record, 3.34 ERA, 1.348 WHIP and 8.2 strikeouts per nine innings with the Space Cowboys.

We have made the following roster moves: pic.twitter.com/qQ7arvelVG

— Houston Astros (@astros) August 3, 2025

Rooney, meanwhile, was 2-1 with a 2.45 ERA, 1.273 WHIP and 12.3 strikeouts per nine innings with Triple-A Jacksonville prior to Sunday's deal.

The 28-year-old southpaw spent the previous seven seasons in the Los Angeles Dodgers' farm system, starting when they picked the then-starter out of Hofstra in the third round of the 2018 MLB Draft. Rooney, who didn't become a full-time reliever until 2023, is 27-19 with a 3.85 ERA, 1.374 WHIP and 9.5 strikeouts per nine innings in his minor league career.

Rooney has faced big league competition in spring training, seeing Cactus League action in each of the last three years. He is 1-1 with a 3.14 ERA, 1.256 WHIP and 8.8 strikeouts per nine innings in those 15 appearances.

First pitch from Boston is scheduled for 11:35 p.m. ET. Rooney is expected to be available out of the bullpen as Houston looks to avoid a sweep.

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