But Claudio Vargas, the frontrunner for the only spot remotely in question, is standing by with a chisel. And Yost conceded that it is Vargas' spot to lose.
"Every year, I come here to try to win my spot," said Vargas, a 28-year-old acquired in a November trade with the Diamondbacks. "I've seen guys come to Spring Training saying, 'I have my spot.' They get lazy. I'm not going to let that happen."
He enjoyed his best start of the spring on Friday, holding a lineup of Angels regulars to two runs and four hits in six solid innings. Vargas walked one, struck out three and needed just 63 pitches to get through his stint.
It was an especially fulfilling performance, since Vargas spent the week working with pitching coach Mike Maddux and bullpen coach Bill Castro on a mechanical adjustment. Vargas shortened his arm path and worked to get "on top" of the baseball, resulting on more downward dive for his two-seam sinker.
Maddux called Vargas "an impatient person," and meant it entirely as a compliment.
"He wants to get it right away," Maddux said. "His attitude is, 'Let's do it.' I love that. We threw one bullpen, and we had it.
"'Claud' is such a good athlete. He's a big guy, but he's light on his feet and he's the kind of guy that can make an adjustment real quick."
Vargas went 12-10 with a 4.83 ERA in 31 games with Arizona last season, setting career highs in wins, starts (30), innings (167 2/3) and strikeouts (123). He produced 17 "quality starts" of at least six innings with three of fewer earned runs.
The Brewers acquired him on Nov. 25 along with catcher Johnny Estrada and reliever Greg Aquino for pitchers Doug Davis and Dana Eveland and outfielder Dave Krynzel.
"Every day, I feel better," Vargas said. "I've been working with Maddux and Castro, and I feel comfortable. They wanted to shorten my arm to get more downward plane, and that's why I got so many ground balls yesterday. We're going to keep working on it."
Asked whether he had a spot in the rotation locked up, Vargas said, "I'm thinking about doing my job. If I don't, they are going to find somebody who will."
Among those potential somebodies is right-hander Carlos Villanueva, who got his turn on Saturday. Pitching in a Minor League game against the Giants' Triple-A squad, Villanueva pitched 4 2/3 scoreless innings, allowing three hits and one walk while striking out four. Forty-nine of his 77 pitches were strikes.
Villanueva is 2-0 with a 3.00 ERA in two Cactus League starts.
Assuming he does not make the Brewers' starting rotation, Villanueva will either start the year in the bullpen or in the rotation at Triple-A Nashville. The latter group could include prospects Yovani Gallardo, Tim Dillard and Zach Jackson.
"We're all kind of stretching out," Villanueva said. "It will be interesting to see how they map that situation out."
Yost insisted earlier this week that the competition is still open. Villanueva's ticket isn't punched just yet.
"He may start in the bullpen," Yost said. "He may start in the starting rotation. That has not been decided yet. But he is right in the mix for making this team. We haven't set anything in our 'pen or our starting rotation."
Yost did say that he likes the depth of the Brewers' rotation, and Maddux argued that "you can't teach experience." Ben Sheets, Chris Capuano, Jeff Suppan and Dave Bush are expected to round out the group, apparently in that order.
"I would say it's a pretty good race right now," Maddux insisted. "Nobody's trying to back into it. Everybody's trying to lead. I love to see that."
Adam McCalvy is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.