Justus Sheffield has been moved from the Triple-A rotation to the Scranton/Wilkes-Barre bullpen with an eye on the left-hander helping the Yankees in September after the rosters expand.

“Hopefully he can play a part in our pen down the stretch and give value toward the end of the season,’’ Aaron Boone said of the 22-year-old lefty who some consider the Yankees’ top pitching prospect.

Scheduled to start against Buffalo on Tuesday night Sheffield instead entered the game in the seventh inning and gave up two hits, an earned run and fanned two in two innings before the game was suspended, tied 1-1, due to rain.

Sheffield was 6-6 with a 2.90 ERA in 21 games (20 starts) this season between Double-A and Triple-A before Tuesday night’s relief outing.