He decided that David Ortiz was too comfortable at the plate and backed him off with a couple of hard ones inside. Then he decided that Ortiz needed a lesson in manners and gave him an earful after Ortiz swung at a 3-0 pitch in a blowout game and started to jog out a shallow fly ball.
What happened after that was, well, about the most entertaining thing that has happened involving the Orioles on a torturous road trip that left them looking like they didn't have a pulse until Ortiz bull-rushed Gregg and cleared the benches.
It wasn't much of a fight. I watched the replay several times and never saw either one of them land anything resembling a punch. But the Orioles didn't back down and they weren't afraid to back Gregg up, either on the field or in the clubhouse after the game.
Center fielder Adam Jones said he "couldn't be prouder" of the way Gregg stood up for his teammates after a series of perceived slights by the Red Sox during their second straight double-digit offensive performance.
"You have to stand up for yourself," Jones said. "I'm not mad at how that situation escalated one bit. We'll just use it as ammo and get after that, and hopefully that energy carries us into tomorrow and the second half of the season."
That opinion was pretty much unanimous. The Orioles were knocked around in Texas and they were embarrassed in the first two games of the series at Fenway Park, so they were almost happy for the opportunity to let their emotions boil over and — just maybe — push back the pendulum before the season completely unravels.
Who knows if it will help, since they certainly didn't respond to manager Buck Showalter's post-game lecture on Wednesday night at The Ballpark in Arlington. They continued to squander opportunities Thursday night and were still smarting after the Red Sox hammered six home runs in the series opener.
If Gregg was trying to send a message to both the Red Sox and his own teammates, Ortiz was an obvious target after he admired his three-run homer off Zach Britton in the first inning and lined a shot off Brad Bergesen's forearm later in the game. Knocking Big Papi off the plate was just old-school hardball, but players have become a lot more sensitive about that sort of thing during the big-money era.
Showalter has been trying to instill a winning attitude in a team that has gotten too used to losing, and this was right in his wheelhouse.
"I'm proud of them," he said. "They handled it the right way."
Though it's a tricky business applauding professional athletes — who are supposed to be role models — for trying to settle their differences with a public fistfight, the incident evoked a well-spring of passion in a banged-up Orioles team that also has been suffering from a bruised ego.
I'm sure there are some well-meaning pacifists out there who are wringing their hands over what kind of message this sends to the children, but it wasn't exactly a hockey fight. In reality, it was more of a team-building exercise for a frustrated team that badly needed something like this to change the subject.
The Orioles have been in a nasty tailspin since they were swept out of Camden Yards by the St. Louis Cardinals at the end of June. The pitching staff has all but collapsed and the hitters have been all but invisible in clutch situations. The Red Sox smelled blood in the series opener on Thursday and showed the Orioles no respect on Friday night. Perhaps most galling to some Orioles players was the way former teammate Matt Albers pumped his fist after several strikeouts.
Of course, the best revenge is playing well, something the Orioles have not done much lately. They can only hope that Friday night's dust-up provides a spark that gets them moving in the right direction.
Listen to Peter Schmuck when he hosts "The Week in Review" Fridays at noon on WBAL (1090 AM) and WBAL.com.