Miley, the game's starting pitcher, expressed visible displeasure during a heated exchange with Farrell after being removed from the game in the fourth inning. Both Farrell and Miley eventually took the exchange, which was captured on TV cameras, into the clubhouse.
Miley had allowed five runs on three home runs to the Baltimore Orioles, nearly as many home runs as he had allowed during all of 2015 coming in to Thursday night's game.
"What happened in the dugout last night was a pitcher who was competitive [and] obviously did not like the decision to be removed from the game," Farrell said.
"But the outburst in the dugout was something that's, you know, unacceptable. I won't stand for it. As a result, we met immediately following the game."
Miley expressed regret for his actions on Friday.
"I handled it terrible," Miley said, noting that he "lost his head."
Miley had a similar exchange during the 2014 season as a member of the Arizona Diamondbacks with Arizona manager Kirk Gibson.
Boston is in last place in the American League East Division with a 27–34 record. Miley is scheduled to start on Tuesday in Atlanta against the Braves.
- Will Green