After testing his stiff neck during batting practice today, Markakis will be in the starting lineup batting leadoff.
It will mark the most consecutive Opening Day starts by an Orioles outfielder since Paul Blair made 12 straight starts in center field from 1965 to 1976.
Schoop, who battled Jemile Weeks for the final infielder spot on the roster this spring, was a September callup last season and played in four games.
"I told him a day or so ago," Orioles manager Buck Showalter said of Schoop. "One thing I've learned about these guys is they can keep a secret. Why that would be a secret I don’t know. He could have told somebody. I think it’s great. I think Jon’s still not sure that he made the club. I had Bobby tell him [in] Norfolk.”
Flaherty spent most of the spring competing for the starting second base job, but he will shift to third until Gold Glover Manny Machado returns from the disabled list.
Showalter delayed announcing his starting lineup because he was waiting to see how Markakis, who has been dealing with neck stiffness since Saturday's flight to Triple-A Norfolk, came out of pregame activities.
"It’s actually moved away from his neck – kind of almost gone to be honest with you," Showalter said before BP. "I don’t see it as anything long term."
If Markakis wasn't able to play, Nelson Cruz would have moved over from left field to right field and David Lough would have received the start in left.
Showalter also said that he told right-hander Tommy Hunter that he will open the season as the club's closer. No surprise there, but he made it official.
"We are going to start out the campaign here, so to speak, with when we get in that [save] situation Tommy will get an opportunity to do that job for us," Showalter said of Hunter, a former starter turned reliever who has never closed out games until now.
"It falls underneath the ‘No [kidding]’ Captain Obvious," Showalter added.
Right-hander Josh Stinson will be the club's long reliever for now, but Showalter said Zach Britton and Brian Matusz could be used in that role as lefties, if needed. One of them would have to remain as the situational lefty.
Here is the Orioles' complete Opening Day starting lineup with their career stats against Lester:
Nick Markakis RF .242 (16-for-66), 6 2B, 0 HR, 1 RBIs
J.J. Hardy SS .296 (8-for-27), 1 2B, 1 3B, 1 HR, 2 RBIs
Adam Jones CF .302 (16-for-53), 3 2B, 0 HR, 5 RBIs
Chris Davis 1B .125 (3-for-24) 2 2B, 1 HR, 4 RBIs
Nelson Cruz LF .455 (10-for-22), 2 2B, 1 3B, 2 HR, 4 RBIs
Matt Wieters C .341 (15-for-44), 3 2B, 1 3B, 0 HR, 8 RBIs
Delmon Young DH .206 (7-for-34), 0 2B, 0 HR, 3 RBIs
Ryan Flaherty 2B Has not faced
Jonathan Schoop 2B Has not faced
Red Sox lineup