Weissert's contract was selected from Triple-A Scranton/Wilkes-Barre on Thursday.
Weissert has served as a high-leverage reliever at Scranton/Wilkes-Barre this year, earning 18 saves while posting a 1.76 ERA and 0.89 WHIP in 46 innings over 40 relief appearances at the Triple-A level. The right-hander hasn't yet made his major-league debut and will likely pitch mainly in lower-leverage situations with the Yankees given the depth of the team's bullpen.