Phelps struck out a career-high 11 batters and allowed just one hit over 6 2/3 innings, dominating the Red Sox's Double-A affiliate in his first Eastern League start in two years as Trenton one-hit Portland, 3-0, at Waterfront Park.
Phelps, who threw 62 of his 94 pitches for strikes, was optioned to the Minors on July 5 to make room for Darnell McDonald, an outfielder New York claimed off waivers from Boston. Phelps' demotion came a day after he allowed a run over 4 1/3 innings in a spot start against David Price and Tampa Bay.
With the All-Star break this week, it's thought the Yankees sent the Notre Dame product to Trenton so he could get in some work building up his pitch count and stay on normal rest.
Phelps could rejoin the Yankees after the All-Star break, though manager Joe Girardi said last week that the plan hasn't yet been discussed.
Phelps can not return to the Majors for 10 days, so the length of his stay in Trenton is unclear. He's pitched well in his two opportunities in the Majors this season, going 1-3 with a 3.05 ERA in 15 outings, including three starts spanning 41 1/3 innings. He's also started a pair of games for Class A Advanced Tampa.
On Monday, the righty was untouchable following a first inning one-out double by Jeremy Hazelbaker and a two-out walk to Reynaldo Rodriguez. He struck out Matt Spring to end the inning, the first of 18 straight batters he retired before departing with two outs in the seventh after fanning Rodriguez.
Trenton reliever Danny Farquhar recorded the final seven outs, striking out three, to complete the one-hitter.
Phelps' effort marked the most strikeouts he'd totaled in a start since he whiffed 10 on July 18, 2010 for Triple-A Scranton/Wilkes-Barre; he also struck out 10 for Trenton on June 20, 2010 in his last stint with the Double-A club.
Trenton gave its starter some early run support on home runs by Jose Pirela in the first and third innings, both off Portland's Caleb Clay. Third baseman Rob Segedin added his first homer in the seventh off Chorye Spoone.