"I'm a Robbie Erlin fan, from what I've seen," Black said. "His time is coming soon."
Erlin was promoted Wednesday, the day the team sent pitcher Thad Weber back to Tucson. Weber had provided the Padres 4 2/3 scoreless innings the previous day against the Brewers and the team needed another long reliever to join Anthony Bass in the bullpen.
The Padres began the season with Bass and Cashner as the long relievers but Cashner has since joined the starting rotation.
In Saturday's 8-7 victory over the Giants in 12 innings, Black used six relievers to cover eight innings. The only reliever who wasn't used was Erlin, though that was by design.
The Padres needed to hold back Erlin in case Sunday starter Jason Marquis departed early and the team needed an arm out of the bullpen capable of working multiple innings.
Corey Brock is a reporter for MLB.com. Keep track of @FollowThePadres on Twitter. This story was not subject to the approval of Major League Baseball or its clubs.