Mayers was designated for assignment by Kansas City on Sunday.
Mayers was removed from both the 40- and 26-man active rosters after allowing six runs over five innings in a no-decision against the Angels on Saturday. If he goes unclaimed or isn't traded, he'll likely report back to Triple-A Omaha to provide pitching depth, but he'll have to be added back to the 40-man roster in order to pitch in the majors again.