Webb was recalled from Triple-A El Paso on Monday.
With Robbie Erlin making a spot start for the Padres on Monday, Webb will join the big club to offer an additional arm out of the bullpen in the event that Erlin is unable to work late into the game. The 27-year-old owns a sharp 1.38 ERA and 15:3 K:BB across 13 innings with the Chihuahuas, but his 8.10 ERA across 3.1 innings with the Padres this season will likely limit him to low-leverage work during his time in San Diego. Carlos Asuaje was sent to the minors in a corresponding roster move.