Pearce will accompany the team to St. Petersburg on Sunday. Jackson has been reassigned to minor league camp and will begin the 2013 season at Triple-A Norfolk, where he could play first base, left field and right field, and serve as the designated hitter. He also could be used at third base.
"I don't want to use something as callous as a flip of the coin, but they're very close, obviously, by taking this deep into it for the role," Showalter said. "Some of it has to do with the way in which we're going to use them. Conor's the type of guy who could come up and take somebody's place potentially as an everyday guy. Not that Steve couldn't, but I think Steve's skills serve the role just a tad better."
Showalter said he made the decision before today's 7-1 win over the New York Mets, "but until some of the balls stopped moving and we kind of saw where we were the day before we broke camp ...
"There aren't many guys in this camp who had the year in the major leagues that Conor Jackson had in 2008 and we think he's close to getting back there. He's in great shape, probably the best shape he's been in in a long time. He's playing very young. And Steve came in in great shape, too. I'm real pleased with what our what-ifs are, so to speak. We're going to have a lot of our bases covered if we have a problem up here with health."
Pearce homered today, giving him seven this spring to go with a .340 average, 18 RBIs and an .851 slugging percentage. He found out before the game that he would break camp with the Orioles.
"I was very relieved," he said. "It was a long camp and it came down to today, and I knew I did everything I could to make this team."
Pearce hadn't spoken to Jackson today about the club's decision, "but we talked during the process a lot," he said. "We were always wondering, 'Did they tell you anything?' We were just trying to get some kind of vibe, what direction they were heading."
The Orioles will have to make a roster move on April 6 when Chris Tillman comes off the disabled list and starts against the Tampa Bay Rays. Showalter said he has three scenarios for clearing space.
"I feel like we've got our options," he said. "We'll see where we are in four days. I'm just excited that Tillman is healthy and ready to go."
Showalter said he still considers Brian Matusz a candidate to start later in the season. For now, Matusz is in the bullpen with two other left-handers, Troy Patton and Rule 5 pick T.J. McFarland.
"I still feel like he's got a chance to be a quality starting pitcher for us, but this is the right move right now for this club," Showalter said.
"If we got a long way away from where he is innings-wise, he'd probably have to make a start or two (in the minors) to get back to that, unless we just happen to fall on the day we need a starter when we have a full bullpen. But he's got probably April before you'd have to do that. But we like our options in Norfolk, too. But we look at Brian as being one of those options, too."
Showalter said he's "excited" about what left-hander Mark Hendrickson could do for the Orioles this season. Hendrickson, who reinvented himself as a side-armer, will be assigned to Norfolk and hope that an opening develops sooner rather than later.
"He had a good spring. He's come a long way," Showalter said. "That was not necessarily a surprise, but something we hoped would kind of take shape, and it has. He's done a good job with us. He's made it interesting."
Hendrickson had the choice of pitching for Double-A Bowie and being closer to his York, Pa., home, "but he wanted to face the better competition," Showalter said.
"Obviously, Mark's not here to pitch in Triple-A very long, in his mind and in ours. We appreciate him having the competitiveness to do this and we'll see where this takes us."
Showalter also said Niuman Romero could play in Bowie as a utility infielder. The Orioles want plus-defenders behind their young pitchers.