The Mets selected Weisenburger's contract from Triple-A Syracuse on Sunday.
The 28-year-old righty will hit the big leagues for the first time after he submitted a 7.22 ERA, 1.57 WHIP and 46:27 K:BB across 52.1 innings at Syracuse. Weisenburger will likely fill a low-leverage role out of the bullpen while he's up in the majors.