BAL@HOU: Martinez blasts a two-run shot in the fourth

HOUSTON -- The Orioles placed Steve Johnson on the disabled list prior to Thursday's game with a left oblique strain and recalled outfielder Xavier Avery to take his place on the active roster. The move gave the team another outfielder until they get Nick Markakis -- who is at his grandmother's funeral -- back on Friday. Avery was optioned to Triple-A Norfolk after the game.

"On the surface, it's an in-and-out [move]," manager Buck Showalter said before the O's 3-1 win against the Astros of adding Avery, who was already on the 40-man roster. "But we're not going to take a chance of not having bullets. He brings a couple things that you can always use in a game. You'd rather err on the side of caution."

The Orioles are doing that with Johnson, who came in on Thursday not feeling any better and will get an MRI in Sarasota, Fla., on Friday. Johnson felt the injury for the first time while warming up in Wednesday night's game and it didn't get any better overnight.

"Don't really know what to expect. It's in an area where if I have it, if I feel it, which I have, yesterday, and it's tough to get over that front side," said Johnson, who struggled to finish his pitches and allowed two home runs over 2 1/3 innings. "So hopefully I'm going to rest it and see. Hopefully it's not a big one. I don't think it feels like it's really a pull, or a big pull. Hopefully it is a slight strain."

Johnson is 1-1 with an 8.49 ERA in five games this season, and his absence leaves the team with a six-man bullpen and a five-man bench. Showalter said the Orioles could opt to add a pitcher before Friday's series against the Rays. They are also hoping to have reliever Pedro Strop (lower back) activated off the DL on Saturday.

Avery, who hit .223 in 32 games last season for the Orioles, got the call at 1 a.m. and hopped on an early morning flight from Louisville to make it to Houston on Thursday morning. After starting the season with Double-A Bowie, Avery played in 15 games with Norfolk, batting .192. He did not play in Thursday's game.

"It's always exciting to come up to the big leagues, to The Show," Avery said of the promotion.