Reynolds and Guerrero were both hit by Red Sox rookie Kyle Weiland, who made his Major League debut, and Orioles manager Buck Showalter said initial X-rays were negative.
"So far, so good," Showalter said. "We will keep an ear out the next couple days and see if they progressively get better to tell you that nothing else is going on there. ... We may have dodged a bullet. But for Vlady to come out of a ballgame, he's pretty sore."
Reynolds was plunked with one out in the third and Guerrero was hit with no outs in the fifth, and both players initially stayed in the game before being lifted. Boston, which entered the game leading the Majors in hit batsmen, hit four Orioles in a two-game span, a fact which didn't sit well with Showalter or his club.
"Judging intent, I don't think there was any intent there on [Weiland's] part," said Showalter, who was ejected along with reliever Michael Gonzalez, who threw behind David Ortiz with two outs into the sixth.
"I just know that we got hit four, five times here and it wasn't particularly pleasant. You are looking at Mark Reynolds and Guerrero having broken hands at the time. It looks like we might have dodged the bullet with the initial X-rays, but you know don't know what could show up down the line. It doesn't make you happy, and it's worked out pretty well for them, worked out real well for them the last four games."
Derrek Lee and Nick Markakis were both hit by Lackey on Saturday, and both benches were warned by crew chief Jeff Nelson, who diffused the situation quickly given Friday's benches-clearing melee -- which saw four ejections between the two clubs.
"I know the umpires are trying, I just wish they would have issued the warnings before the game started," Showalter said, "because Lackey should have been thrown out of the game [on Saturday] for hitting Lee. That was intentional as it gets. [It will] be interesting to see if they hand down any punishment for Lackey."
Brittany Ghiroli is a reporter for MLB.com. Read her blog, Britt's Bird Watch, and follow her on Twitter @britt_ghiroli. This story was not subject to the approval of Major League Baseball or its clubs.