The Blue Jays selected Juenger's contract from Triple-A Buffalo on Saturday.
Juenger has pitched well for Buffalo this season, posting a 3.15 ERA, 1.50 WHIP and 23:8 K:BB with three saves over 20 innings spanning 17 appearances (including two starts). He's taking the roster spot of Austin Voth, who was designated for assignment in a corresponding move. Juenger hasn't tossed more than two innings in any outing this season, so he's likely slated for a role at the back of Toronto's bullpen.