BRADENTON, Fla. -- Orioles right-hander Jake Arrieta tossed four scoreless innings on Monday afternoon against the Pirates, the longest outing by a Baltimore starter so far this spring. Arrieta struck out five and didn't issue a walk, allowing only a pair of two-out hits and looking in complete control against a Pittsburgh lineup with several regulars.

"We didn't really talk about it much but I assumed that I'd go four, depending upon where my pitch count was at that point in time," Arrieta said of his 60-pitch outing. "As far as what's in the tank, I feel like I could go six or seven innings right now. And that's a good feeling to have, to know when there's that much left in the tank when you haven't thrown four innings yet. So, everything is good. Mentally, right where I need to be, and I'll be ready to go next time."

Last year's Opening Day starter, Arrieta is coming off a disappointing 2012 in which he went 3-9 with a 6.20 ERA. He said earlier this spring his focus is on making better in-game adjustments.

"From pitch to pitch, that's a big thing for me and for most guys," he said. "There will be times that I get away from my delivery on certain pitches, but if I can get locked in on a 1-0 count or if I happen to locate a pitch but don't feel great about the way I executed it, I can kind of bounce back and make that adjustment. For where I'm at in my career, I'm getting to the point where I can see those adjustments so much quicker and it's a good feeling.

"I just think today's one step in the right direction. I've tightened some things up, especially the slider. The changeup's still coming along. I want to get that mixed in a lot more. And I think next time out, extended a little further, I'll be able to throw a lot more of those."

Arrieta hasn't allowed an earned run in his last seven spring innings. Overall, Arrieta has made four appearances (three starts) and given up four runs (three earned) on seven hits and four walks, with seven strikeouts over 9 2/3 innings.

"He only had four first-pitch strikes, that's something he has to get better at," manager Buck Showalter said of Monday's outing. "That's why he had some deep counts he shouldn't have. Statistically, results, you see zeros out there. But he's got to get some counts in his factor.

"It was good though, don't get me wrong. He threw the ball well. He was crisp. You can tell he feels good."

Roberts healthy, upbeat midway through camp

BRADENTON, Fla. -- With Spring Training more than halfway done, second baseman Brian Roberts is healthy and upbeat, and the 35-year-old remains confident he will be out there come Opening Day.

"If I was ready on February 24, I hope I'll be ready on April 2nd," said Roberts, who has been a full participant in spring games. "I'm excited. [Orioles manager Buck Showalter] would probably tell you I've been champing at the bit in his ear. I want to play.

"It's been hard to be held back almost. When you haven't played in so long…I enjoy getting my work in on the days when I don't play, but I enjoy the game more than I enjoy the staying back working. I've been back working for a long time, but I know that it's a long season, and we're trying to take the approach that will have me ready to play."

Does Roberts, who suffered multiple concussions and hasn't played a full season since 2009, plan on being able to dive and steal like earlier in his career?

"I don't foresee [playing aggressively] being a problem," he said. "I guess I haven't necessarily. I dove for one ground ball, maybe. I haven't dove headfirst on a steal yet.

My doctors don't foresee it being a problem. I have the confidence now just in being out there every day and feeling very different than I did last year. I think moving forward, everything is in the right place."

Showalter, who joked with reporters to stop jinxing things, has also been encouraged with Roberts' play and enthusiasm this spring. In seven games, he has hit .400 (8-for-20) with a homer and two doubles.

"You can see how excited he is to be back in the flow of what he does," Showalter said. I know he's not on the treatment sheet much at all."

Where a healthy Roberts will be in the Orioles' lineup remains up for debate. He has hit leadoff and second and joked with reporters that he would be OK hitting "anywhere but 10th", meaning so long as he's in the lineup, he's happy.

"That was one of the things that last year people were asking how is it [to watch the team excel from the sidelines], and it was hard, but at the same time I knew I was going to benefit from the great things that were going on eventually also," he said. "And that being able to come back and play this year, I knew that all the good things that went on last year, it was going to be hopefully the tip of the iceberg for what's going to happen this year, we hope."

Three players optioned in second round of cuts

BRADENTON, Fla. -- The Orioles optioned right-handed pitcher Zach Clark, lefty Mike Belfiore and outfielder Xavier Avery to Triple-A Norfolk prior to Monday's game, trimming the Major League Spring Training roster to 53 in the process.

"'X' needs some consistent at-bats to get to where he needs to get," manager Buck Showalter said of Avery, who hit .182 (2-for-12) with two RBIs in 12 games. "He got a little out of whack.

"I think in his mind he's coming in here like every at-bat was like the World Series. I think what will happen is, two or three games down there he will get back in step, relax a little bit. He had a little anxiety, I think. But, pretty excited about his future. We might bring him back, but only if I can play him."

Clark and Belfiore, who were both added to the 40-man roster this winter, will also come over from Minor League camp to pitch for the Orioles again this spring -- likely Thursday -- although they have officially been cut. Clark, 29, went 1-0 with a 3.86 ERA in five spring games (seven innings), while Belfiore went 1-0 with a 2.45 ERA in four games (7 1/3 innings).

"He pitched well the last couple times out, we are very excited to have him," Showalter said of Belfiore, who the organization hasn't decided whether to stretch out as a starter yet. "He really likes the mentality of potentially being able to pitch every day. Him and Clark presented themselves well. If we had more innings, we would have kept them."

Clark, who moved up to Triple-A last year, will be a starter and will get stretched out at Twin Lakes Park to do so. Monday's moves were the second round of cuts, with more coming "Thursday-ish," according to Showalter.

Worth noting

• Jonathan Schoop went 1-for-3 with a walk in the Netherlands' 7-6 win over Cuba on Monday to advance to the championship round of the World Baseball Classic.

• Nick Markakis underwent an MRI on his neck as planned on Monday afternoon, with no news of the results expected until Tuesday morning.

• The Orioles' pregame notes have Dylan Bundy or Kevin Gausman slated to start in Thursday's game vs. the Rays. Both will pitch, but the order is to be determined. Brian Matusz will start Wednesday's game with Tuesday's intrasquad pitchers listed as: Jason Hammel, Steve Johnson, Mike Wright, Jair Jurrjens, Eduardo Rodriguez, Troy Patton and Daniel Schlereth. Hammel and Jurrjens will start the game, with Nolan Reimold, Wilson Betemit and Taylor Teagarden hitting -- along with some of the organization's Minor Leaguers -- to get in some extra at-bats.

• Pitcher Chris Tillman was feeling better on Monday and he planned on playing catch at the team's complex to see how the soreness in his abdomen responds. Tillman was scratched from Sunday's start. He'll also come in on Tuesday to keep getting treatment on the area.

• Tsuyoshi Wada was slated to throw a bullpen session on Monday at the team's complex.