Matusz, sidelined with a left intercostal muscle strain, held the lineup of Nationals Minor Leaguers to a run on two hits and two walks. He struck out two of the 16 batters he faced, inducing nine fly balls and one grounder for the O's Class A Advanced affiliate.
"I feel good. I feel like I want to keep going," Matusz told MLB.com. "I felt like I was just starting to get into a rhythm [after being pulled in the fourth]."
Matusz, who threw 37 strikes, said he expects his next start will be with Triple-A Norfolk or Double-A Bowie. His pitch count would likely be bumped up to the 80-pitch limit for those outings.
"I feel strong," he said. "I've just got to continue to get in work and my innings."
The Nationals managed a run off Matusz in the second frame when Steve Souza worked a one-out walk, stole second and came home on Sandy Leon's single to left.
Potomac tried the small ball approach again in the third against Matusz, who stranded Eury Perez at third after the center fielder laid down a leadoff bunt for an infield single, stole second and took third on an error. Matusz's only other grounder came on a broken bat.
"I felt like once I got on the mound, I was kind of rushing things a little bit," he told MASNsports.com. "My rhythm was a little off. But it was nice to be able to get four ups today. That was big for me. I needed that. I feel healthy. That's the most important thing. I'll just keep it going from there."
The No. 4 overall pick in the 2008 Draft has not appeared in a Major League game with Baltimore since last October. He said he's still got work to do on regaining his rhythm and command.
"It's a start. I need to get my pitches in, because there's definitely some things I need to work on," he told MLB.com. "I made some nice pitches, threw some good changeups and a couple of nice curveballs in for strikes. Fastball command wasn't where I wanted it today -- I was just out of sync with my rhythm."
Matusz lines up to pitch again Saturday and, barring any setbacks, could return to Baltimore next week.