Matusz, among several candidates for the No. 5 slot, was solid Tuesday as the Orioles beat the Boston Red Sox 8-7.
Matusz allowed one run and six hits, striking out two and walking one. The left-hander threw 73 pitches, 48 for strikes.
"That was the goal today, to be able to build the pitch count up and be able to go five innings," Matusz said. "Be able to get through with success, and I'm happy about that."
Matusz gave up a run in the first on a double by Shane Victorino, a single by Dustin Pedroia's single and a sacrifice fly from Mike Napoli.
"I liked the way he came back after the first inning. He threw the ball good," Baltimore manager Buck Showalter said. "His stuff got better as the outing went on."
"He's still one of the competitors. Nobody's really taken a step back. We've got a little less than two weeks. We'll continue to take in the looks that we have and try to make a good decision."
Baltimore led by six runs before the Red Sox scored six times in the eighth off relievers Daniel Schlereth and Adam Russell to tie it. Danny Valencia's solo home run in the ninth put the Orioles ahead.
Ryan Dempster started for the Red Sox, going five innings and giving up three runs on six hits and two walks.
Baltimore got all its runs off Dempster in the third when Trayvon Robinson led off with a homer.
"They bunched some hits together ... but I think for the most part he used all of his pitches. Might not have been as sharp start to finish with his strike-throwing as we've seen in some previous spring training starts here for him," Boston manager John Farrell said. "But like I said, was able to make a pitch and induce a couple of groundball double plays."