Walker was called up by the Mets on Saturday, Bob Nightengale of USA Today reports.

EDGE Analysis

Walker has spent two brief stints in the big-league bullpen, throwing a scoreless inning with a pair of walks against the Rays in mid-May in his lone appearance. He owns a 1.45 ERA in 18.2 innings of relief for Triple-A Syracuse. He'll take the roster spot which had belonged to Zack Muckenhirn, who was optioned to Syracuse in a corresponding move.