Manning was reassigned to the Tigers' alternate training site Monday.
Manning and fellow top pitching prospect Casey Mize were both sent to the Tigers' alternate camp in Toledo. If there was a minor-league season in 2020, Manning would have likely pitched at Triple-A and been in line for a promotion to the majors at some point. That could still happen this summer, but the 22-year-old won't be on Detroit's Opening Day roster.