Markakis underwent a test before leaving to determine the cause of his acid reflux symptoms - the same procedure given to third baseman Manny Machado and left-hander Zach Braddock.
"I had the test done in 2005 and they just wanted to go in and do a checkup and make sure everything was OK," Markakis said.
"I had a little reflux and everything turned out great. No ulcers. Just a little reflux."
Manager Buck Showalter said most of the regulars will play Saturday, but he hasn't made a decision on outfielder Nolan Reimold.
"I don't see limitations on playing him right now," Showalter said. "He's not where he's going to be, but ..."
First baseman Conor Jackson isn't expected to be available Saturday while he continues to receive treatment on his lower back. As I wrote earlier, Jackson hit in the cage this morning and hopes to take batting practice on Saturday.
Jackson probably would play if it were the regular season, "but I'm not going to push that yet," Showalter said. "I'll get an update from Richie (Bancells) about an hour after I leave here."
Adam Jones has been batting leadoff in interleague games to get extra at-bats before the World Baseball Classic, but he's expected to hit lower in the order on Saturday. Showalter will talk it over with hitting coach Jim Presley before making a final decision.
"He's in a good spot," Showalter said. "He'll get enough at-bats."
Chris Tillman,, Brian Matusz, Pedro Strop, Jason Hammel, Wei-Yin Chen, Miguel Gonzalez and Mark Hendrickson will throw bullpen sessions Saturday.
Tsuyoshi Wada sang "Happy Birthday" to himself yesterday, much to the amusement of his teammates.
The Orioles have signed right-hander Kevin Jacob and left-hander Harry Marino to minor league contracts, according to Baseball America's Matt Eddy.