One of the biggest struggles for the A's this season has been the lack of pitching. Heading into the season, it seemed like the team had a solid mix of young talent and proven arms in their rotation, but the original rotation got mixed up really fast.
The Opening Day starter, Luis Severino , only made it until the end of May before he faced off against his former club, the Yankees . He left the start early and has not appeared in a game since. It's also been noted that Severino is expected to miss the remainder of the season.
May 16, 2026; West Sacramento, California, USA; Athletics starting pitcher Luis Severino (left) and catcher Shea Langeliers (right) talk during the fifth inning against the San Francisco Giants at Sutter Health Park. Mandatory Credit: Darren Yamashita-Imagn Images | IMAGN IMAGES via Reuters Connect
Aaron Civale was brought in during the offseason to add a proven arm to the staff, and he got off to a super hot start. His hot start aligned with the A's hot start, as they sat atop the AL West division for a few weeks. Unfortunately, some struggles led to him being dealt to Chicago right after the All-Star break.
Jeffrey Springs , Jacob Lopez , and Luis Morales also highlighted the remainder of the rotation, and all have had their share of injuries or rough starts that led to them being sent to Triple-A.
Jun 16, 2026; Bronx, New York, USA; Chicago White Sox pitcher Joe Rock (46) pitches against the New York Yankees during the fifth inning at Yankee Stadium. Mandatory Credit: John Jones-Imagn Images | IMAGN IMAGES via Reuters Connect
Over the last few weeks, the A's have been feasting on the waivers for pitching. We've seen them add Scott Blewett , Drew Rom , Connor Thomas , and Hayden Juenger, just to name a few. Blewett and Rom have been making a quick impact in the bullpen, and recently claimed Joe Rock could do the same.
On Sunday, the A's announced that Rock had been claimed off waivers. The team immediately optioned him to Triple-A Las Vegas.
Rock has pitched in 10.1 innings this season with the Chicago White Sox . In that time, Rock has allowed just four runs, which is good for a 3.48 ERA.
The southpaw pitched 7.2 innings in the big leagues last season and posted a 2.35 ERA with the Tampa Bay Rays . Now, Rock will look to pitch for his third big-league team.
Jun 24, 2026; Chicago, Illinois, USA; Chicago White Sox pitcher Joe Rock (46) pitches against the Cleveland Guardians during the eighth inning at Rate Field. Mandatory Credit: Patrick Gorski-Imagn Images | IMAGN IMAGES via Reuters Connect
One of the biggest factors that could make Rock a hidden gem is his 90th percentile extension, as well as his unique delivery and funky arm slot.
Rock has mostly been a fastball-slider pitcher, as he throws a sinker only 10% of the time and a changeup 4% of the time.
Mark Kotsay has been big on left-handers throwing more changeups. When they are able to have a strong fastball-and-slider combo and also have a changeup in the mix as well, it could really make Rock unhittable.
Most likely, the A's will have Rock get some work in Triple-A to work on his changeup and increase its usage. If he's able to throw those three pitches well, expect to see the crafty lefty join the A's bullpen before the end of the season.
This article was originally published on www.si.com/mlb/athletics/onsi as Athletics Might Have Landed a Hidden Gem Pitcher .
