WEST SACRAMENTO, Calif. (AP) — New York Yankees pitcher Marcus Stroman experienced a setback in his effort to come back from a left knee injury that has kept him out for the past month. Manager Aaron Boone mentioned that Stroman continued to feel “discomfort” in his knee after a live batting practice session in Tampa, Florida, on Friday.

He will undergo further evaluation before the team determines the next steps in his recovery process. “He’s been receiving a lot of treatment,” Boone said on Sunday. “He just can’t quite get over that final hurdle to really allow him to advance to the next stage on the mound. We’ll keep working to understand it better and ensure we resolve the issue.”

Stroman hasn’t pitched since giving up five runs in two-thirds of an inning against the San Francisco Giants on April 11. He was placed on the 15-day injured list the following day, with Boone initially hoping it would be a brief absence. However, there is no schedule for his return, and Boone admitted that the injury likely affected Stroman’s performance before landing on the IL.

He was 0-1 with an 11.57 ERA in three starts. “In that last start, he just couldn’t really put weight on that front side as needed,” Boone said. “I often say these guys are like race cars, and even a small issue can impact that last bit of control or the extra edge you need. So we’ll continue working to get him where we want him.” Stroman underwent surgery on March 19, 2015, to fix a torn ACL in his left knee and returned to a major league mound on Sept. 12 of that year.

The 34-year-old Stroman is in his second year of a two-year contract worth $37 million. His deal includes a $16 million conditional player option for 2026, which could be activated if he pitches at least 140 innings this season. Last year, Stroman had a 10-9 record with a 4.31 ERA over 30 games (29 starts), throwing 154 2/3 innings—his highest since 2021 with the Mets.

He struggled in the latter part of the season and didn’t pitch in the postseason when the Yankees made their first World Series appearance since 2009. Regarding other injury updates, DJ LeMahieu participated in a rehabilitation assignment for the second consecutive day at Triple-A Scranton/Wilkes-Barre on Sunday and could rejoin the team in Seattle this week to make his season debut. LeMahieu recently received a cortisone injection in his right hip, an issue lingering from last year.