After firing 2 1/3 innings of perfect relief on Tuesday with four strikeouts -- all looking -- Phelps entered Wednesday's game without having permitted a baserunner over his first two appearances in the big leagues, spanning three frames that included five punchouts.
"I wanted to be comfortable, wanted to have fun," the 25-year-old Phelps said. "It's really carried over. I'm having the time of my life right now."
Phelps made the Yankees' Opening Day roster as a long reliever after going 7-7 with a 2.99 ERA in 20 Minor League starts last season, taking a spot that was created by Michael Pineda's right shoulder injury.
A 14th-round pick of the Yankees in the 2008 First-Year Player Draft, Phelps said the most important difference this year has been having the ability to drive his fastball down in the zone and attack hitters.
"I just want to go out there and show them that I can do this," Phelps said. "Go out there, have fun and enjoy it while I can. ... I'm trying to prove to everyone -- myself included -- that I can get big league hitters out. It happens little by little."