Chamberlain fired a scoreless inning, permitting one unearned run, while striking out two against the GCL Pirates in Bradenton, Fla.
Newsday reported that Chamberlain topped out at 97 mph with his fastball.
"My heart was racing, and it's nice to see somebody up there [at the plate] with the guys behind you," Chamberlain told the newspaper. "You sweat a little bit more and the adrenaline's going, but I couldn't have been more pleased with my offspeed stuff. Obviously, my fastball command wasn't where I would like it, but as far as velocity and everything that goes along with that with my arm was great."
The Yankees are hoping that Chamberlain will rejoin the big league roster in August. He is returning from Tommy John surgery performed last summer, as well as an open dislocation of his right ankle suffered during Spring Training in March.