Athletics Place Mark Leiter Jr. on 15-Day IL, Recall Geoff Hartlieb to Replace Him

The Oakland Athletics made a bullpen adjustment on June 20, placing reliever Mark Leiter Jr. on the 15-day injured list with a right hip impingement, retroactive to June 18. The move indicates that Leiter’s availability will be measured in weeks rather than days and creates an immediate need for another arm in late innings.

To fill the spot, the Athletics selected right-hander Geoff Hartlieb from Triple-A and added him to the major league roster. Hartlieb’s recall is the corresponding move to keep the bullpen functional while Leiter remains sidelined on the IL. With the selection of Hartlieb, the team’s 40-man roster is reported to be full.

For Leiter, the key detail is not only that he is on the injured list, but also the specific diagnosis, a right hip impingement. Hip issues for pitchers can affect stride length, release timing, and overall mechanics during long outings. Even when a player is not experiencing sharp symptoms, teams often prefer to err on the side of rest and controlled rehab to reduce the risk of turning a manageable problem into something longer-term.

Hartlieb’s path to the majors is framed by opportunity. When a reliever is sidelined midstream, managers and pitching coaches typically look for someone whose skill set matches the role the team needs most that week and who can handle the routine of being called up quickly. A Triple-A selection generally means the organization believes Hartlieb is ready to contribute, at least for the duration of the roster opening.

From a team-building perspective, the Athletics’ decision reflects the thin margins that frequently exist in bullpen usage. A 15-day IL stint usually changes how the club sequences its relief appearances, including how often it goes to specific setup or high-leverage options. Even without detailing specific usage plans, a new reliever can shift the rhythm of pitching days, the availability of other arms, and the way manager turnarounds play out during a busy stretch.

What to watch next is how Hartlieb is deployed once he joins the bullpen. His early workload, the timing of his first appearance, and whether Oakland uses him as a matchup option or in a more defined bullpen role will help clarify what the organization expects over the coming games. It is also worth tracking whether Leiter’s situation progresses on schedule, since the club’s next roster decisions may depend on the pace of his recovery and how the hip responds to rehab work.