"We've had a couple of lengthy starts lately to freshen our 'pen," Black said.
A bunch of them, as it turns out.
The Padres squeezed six or more innings from their starting pitchers May 24-25 and then from May 27-30. All told, the Padres have done this 18 times in May after just 10 occasions in April.
Black would like to see it done more moving forward, especially with 17 games in June against teams from the National League West.
"If you look at the real big picture, it's not been what you want overall," Black said of the durability -- or the lack thereof -- of the starting staff.
In May, the Padres have had starting pitchers get outs in the seventh inning in 11 of those 18 starts that have exceeded six innings.
That is a big reason why the team took a 14-13 May record into Friday's game against the Blue Jays, the final game of the month.
"Usually when they give you length, that means they're pitching well to give you length," Black said, adding that durability is "what you want and what you strive for. For the job description, it's line one. That one of the things we talk about in Spring Training ... the responsibility of that."
The workload on the bullpen has been reduced because of the longer starts. In April, they ranked eighth in the big leagues in innings by relievers (93 2/3 innings). In May, they dropped to 13th (84).
"We got off to a rough start, and it was not only not giving up runs, it was not giving us innings, not going deep into the games," Padres pitching coach Darren Balsley said. "That was really taxing on the bullpen and taxing on our offense, too. You fall behind by a big margin in the big leagues early, you don't have too much of a chance. Not saying you can't come back, but it's difficult to."