And while it turned out to be just a minor exchange of emotions, it might have sprayed gas on the fire of an already-tight American League East race.
In the seventh inning of the Yankees' 5-2 win, after Boston starter John Lackey plunked catcher Francisco Cervelli, who had hit a home run in his previous at-bat, Cervelli dropped his bat and started walking toward the mound. Sox catcher Jarrod Saltalamacchia promptly stepped in front of Cervelli, at which point the two exchanged words and bullpens and benches cleared.
With both sides shouting across the diamond, Yankees pitching coach Larry Rothschild began arguing with third-base umpire Mark Wegner, who then ejected Rothschild. Both teams were issued warnings.
"It looked a little weird, but I think it's part of the game," said Cervelli. "I've got so much adrenaline, and I maybe need to control it a little bit, but I don't try to do anything bad. It's part of the game. It's Yankees-Boston -- everybody wants to win."
Lackey said that he thought Cervelli's reaction after a fifth-inning home run was unnecessary. After rounding the bases, Cervelli slammed his foot on home plate and smacked his hands together before celebrating with his teammates.
But Lackey -- who leads the Majors with 17 hit batsmen this season -- said he didn't hit Cervelli intentionally.
"I thought it was a little excessive, honestly, but that's not a spot you handle something like that," the pitcher said. "I was definitely not trying to hit him. I was trying to knock him down, for sure. You can see where he stands in the box. You've got to knock him off the plate a little."
Saltalamacchia said he had no problem with Cervelli's fist-pumping after the home run, but he needed to protect his pitcher when Cervelli lost his cool after being hit in the seventh.
"As far as I'm concerned, he's excited to win," Saltalamacchia said. "He's excited for his guys to do well. At the same time, you have to respect the pitcher out on the mound, so certain things, I think, can go too far. To me, the clap at home plate, he was excited. He hit a home run. Second of the year. Good for him."
Saltalamacchia said Cervelli thought he was hit intentionally but later apologized.
Cervelli said he's always been an expressive player, and his display of emotions was even more apparent when he was in the Minors.
"That's my game, and I don't try to show up anybody," said Cervelli. "That's just me, and that's my energy. I don't play every day, so every time I play, I do the best I can."
Lackey also appeared to hit Curtis Granderson in the first inning; a pitch sailed up and in on the Yankees outfielder, making contact with either his hand or his bat. Granderson jumped away, apparently in pain, and began walking to first, though home-plate umpire Ed Rapuano did not reward Granderson the free base.
Yankees starter CC Sabathia plunked Jacoby Ellsbury to lead off the bottom of the first inning, and Matt Albers got a piece of Jorge Posada in the eighth.
In the ninth inning, Saltalamacchia was struck by a Mariano Rivera pitch in the wrist, though Saltalamacchia appeared to swing and Yankees manager Joe Girardi was ejected for arguing the call.
"I think the hype that [the media] builds up can spill over on to the field sometimes, honestly," Lackey said. "The way things are covered sometimes can raise things that aren't really there."
Jason Mastrodonato is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.