Bailey has appeared in four games since returning from Triple-A Lehigh Valley on April 20. He hasn't given up a run in six innings, has surrendered just two hits and has struck out six.
In Wednesday's 5-4 loss to the Cardinals, Bailey pitched around a two-out single to hold what was then a 4-3 Phillies lead.
"I've played at this level before," Bailey said. "Coming into this spring, a healthy Spring Training, I had to put up some good outings, and they felt like I needed to start down in Triple-A. For whatever it is, we're here playing good baseball now. That's behind us, and we just keep moving forward."
On April 30, Bailey earned his first win since June 18, 2013, pitching a scoreless seventh in a 4-3 win over Cleveland.
"It's definitely nice to come in and, as a bullpen, do it together," Bailey said. "I was just the lucky one who got the 'W.' For me, it was a long time coming, but nothing comes easy. Hopefully, I stay healthy the rest of the season."
Bailey's fastball has dipped a couple of miles per hour since his days with Oakland, when he hit 94 mph on the radar gun. But it is still in the low 90s.
"His fastball has got a natural cut action to it, which is a pretty sharp cut action, which is really effective," Mackanin said.
Just as important, Bailey provides veteran leadership to a young group.
"For us, it's about handing the ball off to the next guy, and there's no egos down there," Bailey said. "It's easy to pitch when the group is like that."