Slowed by left elbow discomfort, it took a while for Wada to make his first appearance this spring, when the team moved him along cautiously after he had his elbow drained early in camp.
Showalter wants Wada to "get to 90 pitches" in each outing to essentially prove he has made strides in his arm strength. Wada will make his first extended spring training outing on Monday.
"He's progressing well, and he's close," Showalter said. "I like what I've seen from him. He's moving along real well. I think he's going to help us when he gets to 100 percent."
After surrendering a run and a hit in two innings in a March 18 outing against the Braves, Wada said he wouldn't be ready for the regular season following his March 27 appearance, in which he was charged with four runs on four hits in three innings against the Twins.
But on Tuesday, Wada sounded a bit more confident about his chances. Speaking through interpreter Seob Yoon, Wada said he had "no problem at all" in being physically strong enough to start the regular season with the team.
"I felt a lot better than last time," said Wada, who tossed 75 pitches, 50 strikes on Tuesday. "My fastball is a lot better. There was a little bit of hop on it today. The curveball, all the breaking balls, were a lot better than last time."
Wada did sound a bit tentative, though, when pressed about his readiness, saying "his condition is normal, not really good, not really bad." He added that if he was going to throw next week in the role as the fifth starter, he would have to work on his condition to get ready for the season.
"I wanted to go to Baltimore with the team, so it is a little disappointing, but I think the team gave me another chance to adjust to the schedule," Wada said after finding out about the decision. "I would like to use this opportunity as much as possible.
"Physically, I'm ready right now. I'd like to pitch much better. ... I am motivated to show [Orioles management] I am ready to pitch on the big league level."
Wada, who signed a two-year, $8.14 million deal this winter with the Orioles, posted a 1.51 ERA in 184 2/3 innings for the Fukuoka Softbank Hawks in Japan in 2011.
With four of the team's five rotation spots guaranteed -- with Opening Day starter Jake Arrieta, Jason Hammel, Wei-Yin Chen and Tommy Hunter -- Brian Matusz appears to have locked up the fifth spot, although Showalter would not affirm this information.
With the move, the Orioles now have 26 players in camp. Showalter said the team will make the final cut sometime before the deadline on Wednesday at 5 p.m. ET.