But Nos. 4 and 5? Those spots remain up for grabs, but consider the 22-year-old Maurer as having made as strong a statement as possible after lowering his Cactus League ERA to 0.90 with five more shutout innings in Monday's 16-0 victory over the Reds.
Veteran Jeremy Bonderman will get his final spring start Tuesday against the Royals, and he remains in the hunt as a non-roster invitee. Blake Beavan, meanwhile, has had a strong spring until a poor outing his last start. Beavan entered as the favorite coming off an 11-win season in 2012.
Erasmo Ramirez appears the least likely to crack the rotation at this point after a tender triceps muscle limited his work last week. He'll now pitch out of the bullpen for a second game in a row Wednesday.
Wedge acknowledged the choices are close at hand, but nothing has been finalized yet.
"We're trying to go all the way through," he said. "Part of my discipline is just keeping your mind open to the very end, which is approaching very quickly here. We'll see how the next couple days play out, but it's safe to say we're getting very close to making the decisions we need to make."
Maurer, last year's Southern League Pitcher of the Year for Double-A Jackson, could be making it impossible to ignore his spring. The 6-foot-5 California native gave up six hits in five innings with one walk and seven strikeouts, holding the Reds to 0-for-5 with runners in scoring position -- even in a game that slowed to a crawl as the Mariners scored early and often.
"He threw the ball well today," Wedge said. "Sometimes it can be difficult in a game like that, where you're sitting in here like he did. To be able to hang onto it and maintain that consistency was pretty impressive. He threw the ball well against a good group of hitters over there."
Maurer acknowledged he gets extra geared up when runners reach base, which they did in all five of his innings.
"You just can't let them score. You can't let them put that run on the board," he said. "Maybe I bear down, I don't know. I'm not sure if I'm doing anything different or just making pitches when I need to make them."
Maurer now has six walks and 22 strikeouts in 20 innings this spring. On Monday, he blew down cleanup hitter Ryan Ludwick with the bases loaded in the third and caught All-Star first baseman Joey Votto looking with a runner on third to end the fifth.
"I wouldn't say it was anything we hadn't seen, but it reaffirmed some things we'd seen, in regard to making pitches in big situations," said Wedge.
As for Ramirez, Wedge said the 22-year-old needs to be "built back up" after a sore arm limited him to a two-inning relief stint last week. He didn't rule out having Ramirez start the year in the bullpen, but said that wasn't the primary focus right now.
"I still want to build him up," Wedge said. "We know he's capable of pitching in the bullpen for us. Obviously, he did that for us last year as well as starting, but right now I just want him to go out there and pitch healthy. That's the most important thing. He felt good in his bullpen the other day, so my focus is on that right now."
Bonderman, who hasn't pitched in the Majors since 2010 due to a variety of shoulder and elbow issues, will need to continue progressing Tuesday. He comes in with a 7.20 ERA this spring, but has added an inning in each of his five outings and gained velocity and confidence as he's gone.
"I just want him to keep doing what he's been doing," Wedge said. "He's really done nothing but progress this camp. He just keeps getting better and more consistent. You're seeing him pitch with good stuff, and he continues to expand upon that. So we just want to see him push forward with that.
"He's different now," said Wedge. "He's more of a complete pitcher, if you ask me. I saw him really good over there in Detroit, but right now he's a guy that goes out there with pitchability and better movement on all his pitches. It's been fun to watch him."