During the recent road series against the Boston Red Sox, there were times when it looked as if Manny Machado and Mookie Betts were trading line drives and waiting to see who blinked.

In Tuesday night’s game between the Orioles and the Washington Nationals, Bryce Harper hit a first-inning home run and Machado answered with his own in the bottom of the inning.

If it seemed as though three of the most exciting young players of their generation were engaged in a personal competition at the plate, Machado said Thursday that such appearances are deceiving.

“It’s just pure coincidence,” Machado said. “It’s just a feeling of going out there and trying to do anything you can to try and feel good. Try to get a pitch you can drive. When you’re going hot, you’re going hot. When you’re not, you’re not. At the time, we were hitting the ball pretty well, so I guess at the end of the day it’s just coincidence.”

Machado had to be reminded about a particular game (May 18) in which he and Betts hit sizzling line drives in each of their first three at-bats. Machado hit a screaming double to left in his first at-bat. Betts hit one to center in the bottom of the same inning. Machado doubled sharply again in the third inning and answered with a homer. Both hit balls very hard again for hits in the fifth inning.

“Obviously, I’m watching,” Machado said. “He’s hitting the ball hard. He hit a home run that game I think. We’re playing defense at the same time, so you kind of see it, but I don’t put in that perspective that we’re going back and forth.

“All I’m thinking is, ‘Don’t pitch to this guy. Don’t give him anything good to hit.’ I’m sure he’s thinking the same thing. That’s our mentality in the game.”

Peterson faces former team: The last time the Orioles and Yankees faced off in the first week of the season, Jace Peterson was in the home pinstripes and playing well during a brief minor league call-up with New York.

Thursday night, he was given the chance to bat leadoff against his former club as part of an extended opportunity with the Orioles as they look to cover the absence of infielder Tim Beckham, who is out after undergoing core surgery. It’s a chance Peterson, a 28-year-old 2011 first-round draft pick who is with his fourth major league team, is happy to have. And it’s one manager Buck Showalter seems glad to give him.

“Jace is a baseball player,” Showalter said. “I’ve been real pleased with, knock on wood, how he’s played third base.”

Peterson arrived batting .300 in 10 at-bats with the Yankees, and has started 22 of the 32 games the Orioles have played since he arrived, batting .171/.300/.263 in that span. More important to the Orioles is that he’s made just two errors on the infield while replacing Jonathan Schoop, who had been out with an oblique injury, and then Beckham.

“I’ve enjoyed it,” Peterson said. “I think that defensively, I’ve been playing pretty good. Offensively, I kind of started off good but it’s been slow. Hits have been few and far between, but for me it’s definitely been a great opportunity and I’m grateful for it.”

O’Day and Rasmus headed for rehab stints: Manager Buck Showalter said reliever Darren O’Day is doing well and should be ready to rejoin the bullpen soon.

“It looks like he’s definitely going to have a rehab appearance down below,’’ Showalter said. “At least one.”

Showalter also said he was told by director of player development Brian Graham that outfielder Colby Rasmus (hip) might start a rehabilitation assignment with the Bowie Baysox as soon as tonight.

Britton sharper than expected: Closer Zach Britton’s first rehab appearance went better than expected, according to Showalter.

“I actually wasn’t expecting him to be that crisp or that sharp,” Showalter said of Britton’s single-inning stint Wednesday night for the Baysox in Wilmington, Del. “I don’t know if it was intentionally, but he came in against three left-handed hitters. I don’t think that’ll happen a whole lot during our season. Good start. Couldn’t ask for more.

“So we’ll take a look at the weather and see where he goes next and see where it fits in the schedule.”

Around the horn: New father Danny Valencia informed the club that he will return from his brief stay on the paternity list in time for tonight’s game. Reliever Donnie Hart, who replaced him on the roster, remained with the team for Thursday night’s game.

peter.schmuck@baltsun.com

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Baltimore Sun reporter Jon Meoli contributed to this article.