The White Sox turned blocked infielder Oliver Dunn into 25-year-old lefty Joe Rock, a former Rays starter with swing-and-miss stuff and enough upside to become an MLB bullpen option sooner rather than later.
In the midst of Tuesday night's game against the Seattle Mariners, the Chicago White Sox found time to make another trade.
The White Sox acquired left-handed pitcher Joe Rock from the Tampa Bay Rays in exchange for infielder Oliver Dunn. Rock has been sent to join Triple-A Charlotte, but will have a place on the White Sox 40-man roster as Kyle Teel gets transferred to the 60-day injured list.
Rock is a 25-year-old lefty who spent his entire minor league career as a starting pitcher before making the transition to a relief role in 2025. That was also the year he made his MLB debut.
Rock debuted for Tampa Bay on June 28, 2025, and appeared in three games in long relief, posting a 2.35 ERA in 7.2 innings with a very impressive 11 strikeouts.
Rock hasn't had the same success this year in the minor leagues. He's made 13 appearances with AAA-Durham and has a 5.40 ERA in 15 innings. The upside needs no explaining. He has 27 strikeouts in 15 innings pitched this season for a reason.
Rock has some funky stuff that helps him miss a lot of bats and generate soft contact. He is in the 90th percentile or better in K-rate, whiff rate, zone contact percentage, hard-hit percentage, average exit velocity, and ground-ball rate among all pitchers at the Triple-A level. The problem, of course, is the control.
Rock has issued 17 walks in 15 innings in 2026. That's 10.2 walks per nine, which is completely out of character compared to his career minor league rate of 3.4 walks per nine.
If the White Sox can iron out some of those issues, they could be getting an effective lefty reliever here with club control and a lot of upside.
Chicago has tried carrying three left-handed pitchers in the bullpen for most of the year, but it's been difficult to find a competent third arm to go with Bryan Hudson and Sean Newcomb. Tyler Gilbert struggled. Tyler Schweizer struggled. And Brandon Eisert, the current guy on the active roster, doesn't really move the needle.
While Rock will start in the minor leagues, it wouldn't surprise me if he joined the White Sox in the near future.
It's worth a shot from Chicago's front office. It only cost them Oliver Dunn, a 28-year-old infielder who, yes, has had a ton of success in Triple-A this season with nine home runs and a .938 OPS, but also doesn't have a path to regular playing time or even a roster spot with Chicago. The infield is currently the organization's strength.
Not to mention the fact that Dunn has 131 career MLB at-bats and a .551 OPS. I don't think the Sox will miss him, so any value they're able to get from this trade makes it worth making.
