That is, except when it comes to Pat Neshek. And it's not much of a mystery to Mackanin as to why.
"Well, he hasn't given up a run," the manager said Saturday while softly hitting his office desk. "Knock on wood."
Indeed, the 36-year-old right-hander has yet to allow a run in his 13 appearances, the only Phillies reliever with double-digit outings to do that.
Neshek was acquired by Philly last offseason after he spent two quality seasons with the Astros, primarily as a situational right-hander. But Mackanin has already showed that he's not afraid to use the veteran reliever a little differently.
"When he was with St. Louis [in 2014], he had pretty good numbers against lefties, but for some reason [Houston] didn't want him to [do that]," Mackanin said. "He's faced some lefties and done OK, but we need him to feel totally confident about being able to do that without wondering [if he can]."
Left-handers are 3-for-21 against Neshek this season, and right handers are 5-for-22 off him. In other words, he's getting everybody out these days. That begs the question of whether or not Mackanin may use Neshek in the later innings to aid his maligned closer situation. But it appears Mackanin wants to keep Neshek in the spot he's in for now.
"Neshek and [Joely] Rodriguez somewhere in the sixth [inning], somewhere in the seventh type of thing, [Joaquin] Benoit and [Hector] Neris [later], that's what I'd like to do," he said. "At some point I'd like to bite the bullet and just go with something."
The Phillies are 22nd in the Majors with a 4.66 bullpen ERA, and are tied for the lead with 22 home runs allowed. Despite that, Mackanin remains confident a rebound is around the corner.
"I still feel like our bullpen is gonna be a good one," he said. "We've got interchangeable parts with Neshek, [Edubray] Ramos and Benoit and Neris."
Daniel Shiferaw is a contributor to MLB.com based in Washington. This story was not subject to the approval of Major League Baseball or its clubs.