Matusz, who is coming off a rough 2011, is one of the major storylines for the Orioles this spring, and he arrived in camp early and in noticeably better shape.
But how will that translate into pitching?
"He's gained a lot of confidence with the conditioning he's done," pitching coach Rick Adair said. "Through the conditioning he's gotten to the point where if he runs into obstacles physically, he can now make adjustments in his delivery, whereas before he had so much weakness that he really couldn't do it physically. Even though he wanted to do it, he just couldn't."
Adair, who has been impressed with Matusz's early throwing sessions, said one of the telling signs Matusz is on the right track is the spin on his two-seam fastball, which has consistently been there.
Both Matusz and right-hander Alfredo Simon -- who will start Monday's 1:05 p.m. ET away game against the Rays -- are looking to start things on a high note and ultimately claim a spot on an Opening Day roster that is very much in flux.
The rotation competition, which figures to include at least a dozen candidates, will become clearer by mid-month, when the team will need to start figuring out which pitchers would be better suited for the bullpen.
Matusz's spring -- as well as the status of Zach Britton, who has been slowed with inflammation in his left shoulder -- will play a role in determining who heads north, as will the performances of Tsuyoshi Wada and Wei-Yin Chen. Wada is dealing with inflammation in his left elbow and will be monitored closely, as will Chen, as the two adjust to Major League Baseball.
There are plenty of other camp battles, including two bench spots (at least one of which will be given to a utility player) and a bullpen that is as wide open as the rotation. Baltimore has 10 players who are out of options -- meaning each would have to be exposed to waivers before being sent to the Minor Leagues -- putting the Orioles in a position to make several trades.
"It will all sort itself out," Dan Duquette, executive vice president of baseball operations, said of the roster constraints.
Though Duquette said the team is likely done adding for now -- and will evaluate what it has in camp -- he didn't rule out a mid-spring acquisition, either through free agency or a trade.
In addition to their pitchers, the Orioles will closely monitor the progress of second baseman Brian Roberts (concussion) and right fielder Nick Markakis (abdominal surgery). Though Roberts' timetable is unclear, Markakis is aiming to get into games in mid-March, and he is targeting being a go for Opening Day. The team's lineup will be varied this spring, especially the first few weeks without Markakis, and manager Buck Showalter will also experiment with finding a leadoff hitter in lieu of Roberts.
"We will have some versatility to the batting order," said Showalter, who has more flexibility with Wilson Betemit, who is capable of playing the field, at designated hitter. "I actually think the four-hole is going to be more of a challenge than the one-hole for us to figure out. There are certain things that a guy's assured of when he comes to bat more often than not."
In addition to Monday's home opener, the other Orioles games that will be aired on MLB.TV this spring are: March 10 at Philadelphia, March 11 vs. Boston, March 18 (split squad) at Atlanta and vs. New York, March 23 vs. Boston, March 24 vs. Washington, March 25 at Philadelphia, March 26 at Pittsburgh, March 29 at New York and April 1 vs. Tampa Bay.