HOUSTON – Right-hander Steve Johnson was hoping the discomfort in his left oblique, which cropped up during his relief outing Wednesday, would go away overnight.

It didn’t, and on Thursday afternoon Johnson was placed on the 15-day disabled list for the second time this year. The team called up outfielder Xavier Avery from Triple-A Norfolk to take his roster spot. (Avery was sent down after the game, with the team expected to add a reliever to the roster Friday.)

“It’s real frustrating,” said Johnson, who missed the beginning of the season with a lat strain. “Obviously I don’t want to spend any time on the DL, and this is going to be my second stint of the season. I’ve been a guy -- until last year really with the groin -- I had never gotten hurt before. Really, really frustrating.”

The St. Paul’s graduate is scheduled to fly with the Orioles to Tampa on Thursday night and then report to the club’s spring training complex in Sarasota, where he expects to get a MRI sometime in the next few days. The club won’t know the severity of the strain – or a projected timetable for return – until after that.

“I’ve never had it before.  Don’t really know what to expect,” Johnson said. “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. Rest it and be able to get back.”

Johnson was 1-1 with an 8.49 ERA in five games (four starts) with the Orioles. In 2012, he was 4-0 with a 2.11 ERA.

“He pitched well for us last year, we know what he is capable of,” Orioles manager Buck Showalter said. “I think because of some of the issues he had with his leg, his offseason conditioning didn’t get to where it needed to be. I think some of these things are a break off of that, if I had to hazard a guess.”

Avery, who batted .223 in 32 games for the Orioles last year, was in Louisville when he received a call at 1 a.m. telling him he needed to get on a 6 a.m. plane to Texas. The former second-rounder batted .300 in 39 games at Double-A Bowie this year before being promoted to Triple-A Norfolk, where he hit .192 in 15 games.