Ramirez was optioned to Triple-A Scranton/Wilkes-Barre on Thursday.
Ramirez has pitched well this season with a 2.67 ERA and 25:9 K:BB over 33.2 frames, but he finds himself back in the minors nonetheless. The Yankees haven't announced a corresponding move yet, but it's expected to be Randy Vasquez coming up to start Friday in Miami.