SARASOTA, Fla. -- Orioles pitcher Tsuyoshi Wada threw 20 pitches off of a half mound Monday morning at the Ed Smith Stadium Complex, as the lefty continues to progress from Tommy John surgery last May.

Wada, speaking through interpreter/athletic trainer Seob Yoon, said he will repeat the session -- which started with long toss -- Wednesday and Friday, and if all goes well, he will throw off a regular mound for the first time next Monday.

When asked if was excited about the progress, Wada didn't need anything translated.

"Yes," he said with a grin. "Yes. [It was] real good."

Wada had been on the half mound before Monday, but this was the first time he threw with some effort and he estimated it was about 70-80 percent of his normal effort.

"I do feel better day by day," said Wada, who could be back with the Orioles in May or June.

Ayala decides not to play for Mexico in Classic

SARASOTA, Fla. -- Orioles reliever Luis Ayala has decided not to pitch in the World Baseball Classic, opting to remain in Major League camp rather than accepting Team Mexico's invitation.

Ayala, who was in limbo when asked by reporters on Monday morning, informed pitching coach Rick Adair of his decision later in the day.

"It's got to be a tough decision," Adair said of Ayala, who has pitched for Team Mexico in the Classic. "You won the Caribbean Series [in winter ball], go through all that. Obviously he loves his country. But [for] whatever reasons he has decided not to, and I'm sure he's kind of gone back and forth on that."

Ayala went 5-5 with a 2.64 ERA over 75 innings pitched last year, and after pitching winter ball, the Orioles have been careful in slowing him down this spring. Having the 35-year-old stay in Spring Training is a plus for manager Buck Showalter and Adair, who can monitor his workload.

"We can have him simulate games, pitch in Minor League games and build him without the pressure of competition this early in the year," Adair said.

"It's a catch-22 because there's a lot of guys that -- I went through it myself -- you come back from winter ball, you pitched a lot of innings and it's how much time to take off, when to get ready, do you stop completely? Obviously he's not stopped completely, but we've got to stretch out the recovery time but still pitch. It's going to take a lot of input from Luis as to how he's feeling as to what we do."

Machado, Braddock out, expected back Tuesday

SARASOTA, Fla.-- Third baseman Manny Machado and pitcher Zach Braddock did not work out with the Orioles on Monday, as the pair had to undergo additional procedures as part of their physicals.

The club said it was minor and both are expected back in Major League camp on Tuesday.

Machado, projected to be the Opening Day starter at third, is in his first big league camp coming off a rookie season in which he hit .262/.294/.445. Braddock -- who is rehabbing back from surgery to fix a left labrum tear -- signed as a Minor League free agent this winter.