Manager Buck Showalter revealed Monday that Walker underwent a right knee procedure Jan. 14, Joel Sherman of the New York Post reports.
Walker is behind some of the Mets' other starting pitchers early in camp following his offseason surgery, but Showalter is hopeful that the right-hander still has a chance to be ready in time for Opening Day. In his first season with the Mets last year, Walker posted a 4.47 ERA and 1.18 WHIP in 30 appearances (29 starts). While any potential absence to begin the 2022 campaign would likely be a short-term one, Tylor Megill and David Peterson would be candidates to fill in if Walker is forced to miss time.