SARASOTA, Fla. -- While the question marks surrounding the Orioles' pitching staff has dominated early spring headlines, one of the most interesting battles is for the two bench spots, which will largely be a function of several factors.

Right now, outfielder Jai Miller and infielders Matt Antonelli, Ryan Flaherty and Steve Tolleson are essentially competing for two roster spots. Antonelli, Flaherty and Tolleson are utility guys, and with utility player Robert Andino penciled in as the Orioles' starting second baseman given Brian Roberts' uncertain status, manager Buck Showalter said one of the tie-breaking factors between the trio will be the ability to play shortstop and backup J.J. Hardy.

Miller can play all three outfield positions, and if either Antonelli, Flaherty or Tolleson don't prove to be capable in the outfield, the team could take just one of those players and Miller, who would be the team's fifth outfielder. With designated hitter Wilson Betemit not a strong fielder, the Orioles -- on paper -- are an outfielder short. Assuming right fielder Nick Markakis (abdominal surgery) is ready for Opening Day, Baltimore could opt to keep two of the those three utility players over Miller, although it would risk losing the outfielder, who is out of options, on waivers.

"If you look at [Endy] Chavez and Nick being left-handed bats, he's a guy who could fit in as an extra player," Showalter said of Miller, who was acquired in an offseason trade with the Oakland Athletics. "That's really what his niche is coming in. We've got to get our arms around him defensively and see what he is."

The 26-year-old Miller has played all three outfield positions in the big leagues and hit .276 with 32 home runs and 88 RBIs in 110 games for Triple-A Sacramento in 2011. He also appeared in seven games for the A's, going 3-for-12 with a home run, and the Orioles are intrigued by some of his skills -- including baserunning and speed.

"I just want to show them that I can help the team in any possible way," Miller said of his mind-set this spring. "You try not to focus on [being out of options], because at the end of day, you can't do anything about it. Me, personally, I try to just focus on the things I can control, and that's me playing hard."

Miller, who was roommates with Andino in Class A ball as prospects in the Marlins' system, has struggled with high strikeout numbers in both the Major and Minor Leagues, a significant statistic given both Mark Reynolds and Chris Davis figure to be in the Orioles' lineup.

"It's definitely something I work on, focus on all the time, something I would like to do better with," said Miller, who had 179 strikeouts in 475 plate appearances at Triple-A last season. "But at the same time, you don't want to be up there thinking about it."

Tidbits

• Reliever Jim Johnson (lower back) threw 25 pitches off the mound with no problems Tuesday morning, and he'll pitch again on Friday and Monday. Johnson also took part in some pitchers' fielding practice for the first time.

• Alfredo Simon will open the Orioles' Grapefruit League slate Monday at 1:05 p.m. ET vs. the Rays, and then in a 7:05 p.m. contest that will air on MLB.TV, Brian Matusz will start against the Pittsburgh Pirates. That should answer questions regarding Simon being considered a starter (at least at first), with the team expected to start breaking off starters and relievers around March 15.

According to manager Buck Showalter, "about 80 percent" of the decision of who will pitch first had to do simply with someone just needing to be first, although part of that thought process also had to do with the organization wanting to make things relatively smooth for Matusz, who is coming off a tough 2011 season.

"I'd be less than frank if I said that doesn't figure into it," Showalter said, "but you can say the same thing about four or five other guys, too."

The plan is for Simon and Matusz to go two innings each.

• Top prospect position players Manny Machado and Jonathan Schoop reported to the Ed Smith Stadium Complex on Tuesday afternoon and will be in big league camp the next few days. They could also be used in the team's intrasquad games later in the week.

• Showalter said Nick Markakis (abdominal surgery) won't get into games until at least March 10, and it could be later than that as the club is erring on the side of caution. The goal is still for Markakis to be ready by Opening Day.