In addition to the Yankees' original complaint to Major League Baseball about the Red Sox stealing signs, New York also alleged that pitcher Doug Fister used an illegal earpiece.
According to CSNE, the Yankees thought Fister was using the earpiece during his start last Friday in the Bronx. However, after watching a replay of the game, it was determined that Fister had put his mouth guard on his ear after finish his outing. In the start, Fister allowed one run over seven innings.
This complaint was separate from the investigation of the Red Sox taking signs through the use of an Apple Watch.