Conner Mantz has withdrawn from the USATF Cross Country Championships, confirming in a new Instagram post that the injury he mentioned last week has not resolved in time for him to race.
The American marathon record holder wrote that his original plan was to end the year in Portland to try to qualify for the 2026 World Cross Country team. Instead, he said he “was too excited to get back to training after the Chicago Marathon” and will now miss the race because of the injury that has kept him out through November.
The update follows what we reported last week, when Mantz first acknowledged the issue in a Strava comment.
His training log had shifted sharply at the time: only 10 miles of running for the week and a series of long elliptical and arc-trainer sessions replacing his usual mileage.
Responding to a follower under one of those cross-training uploads, Mantz wrote that he had a “little injury,” was still waiting for a diagnosis, and hoped to return in time for US cross.
That return won’t happen in Portland. Mantz has not shared the diagnosis, but the continued lack of running suggested the timetable was getting tight. His withdrawal confirms that whatever was bothering him two weeks ago hasn’t cleared.
The USATF Cross Country Championships serve as the selection race for next year’s World Championships in Tallahassee. Mantz had circled the meet as a late-season target after a career-defining 2025 in which he set American records in both the half marathon (Houston) and the marathon (Chicago).
His absence comes after a heavy stretch of racing this fall.
Between his record run in Chicago and pacing his wife Kylie through her full marathon debut in Fresno on November 2, Mantz had put in two marathon-distance efforts less than a month apart. Mantz never linked those efforts to the injury and hasn’t suggested a cause, but the training shift became obvious through his Strava uploads.
He closed his announcement by wishing the U.S. team well and signaling that the next phase of training starts once he’s healthy: “I’m bummed to not be competing in two weeks, but excited for the team the US puts together. On to 2026.”
