The 22-year-old topped an impressive run with Double-A Huntsville by pitching even more effectively for Triple-A Nashville, where he had gone 2-0, 2.16 through his first four starts.
"That's definitely a good sign," Brewers minor league pitching coordinator Lee Tunnell said. "That's what you like to see."
Peralta earned his promotion by going 9-7, 3.46 in 21 starts at Huntsville. He collected 117 strikeouts and allowed 106 hits and 48 walks in 120 innings. Hardly intimidated by facing Triple-A batters for the first time, Peralta struck out one-third (33) of the first 98 he faced, while allowing just 26 baserunners in 25 innings. Opponents had batted .174 without a home run.
Peralta's second start, against Tucson, was particularly impressive. He went seven shutout innings, allowing three hits and no walks with nine strikeouts.
It wasn't until Peralta's fourth start with Nashville that he hit his first speed bump, losing his fastball command and issuing seven walks in five innings against a hard-hitting Memphis squad. Even with that difficulty, he surrendered just two runs.
"He was rushing to the plate a little and that led to some walks," Nashville manager Don Money said. "But he still battled and gave us a chance to win. That's what you like to see when you don't have your best stuff."
A long-time minor league skipper who offers balanced player evaluations, Money had not seen Peralta pitch much until he arrived in Nashville. To say the least, Money was suitably impressed with the repertoire of the 6-foot-2, 240-pound righthander.
And why not? Peralta has flashed a fastball that reaches 96-97 mph at times and regularly sits at 92-94. He also throws a sharp-breaking slurve and deceptive changeup. That repertoire has allowed Peralta to mature into a pitcher, not just a thrower.
"I was a little surprised," Money said. "He's still a young pitcher. I didn't know much about him, but he's willing to listen and work. He's a down-to-earth guy.
"He has the velocity, the breaking ball and changeup to be a pretty good major league pitcher. He gets a lot of swings and misses. When I'm coaching third, I talk to the other team's third baseman a lot and they all say this kid has some good stuff."
This is what the Brewers had in mind when they signed Peralta as a raw 16-year-old with a strong arm out of Samana, Dominican Republic, in November 2005. He faced major adversity almost immediately, having Tommy John surgery and missing the entire 2007 season.
As might be expected, it took Peralta some time to get his game back together, and the Brewers made sure not to rush him. After pitching the entire 2009 season at low Class A Wisconsin, he moved up a rung to high Class A Brevard County last year, then up to Huntsville for the final weeks.
Now, Peralta finds himself one step from the major leagues as a still-young pitcher. With a deep big league rotation headed by Zack Greinke, Shaun Marcum, Yovani Gallardo, Randy Wolf and Chris Narveson, the Brewers had no need for Peralta's services this season, but his upward momentum bodes well for 2012.
Nearly Ready For Prime Time
Righthander Mark Rogers opened the season as the top pitching prospect in the Brewers organization, in part because of his rise to Milwaukee last September. Rogers lost his footing, though, as he pitched poorly for Nashville, running up a 13.20 ERA in five starts, before having surgery in August on both wrists to alleviate pain caused by carpal tunnel syndrome.
That development opened the door for Peralta, if he wasn't already on the way with his 2011 performance.
"I'm not surprised by what he's doing," said Tunnell, who watched Peralta make five starts at Huntsville before moving up. "I see him as a solid big league starter, maybe in the middle of the rotation.
"He's following the developmental model we have set in the organization. He has mixed in a two-seamer this year and that has become a very good pitch for him. He's doing more with his fastball now, and that's very encouraging to see. He's a real bright spot for us."
Tunnell calls Peralta a "baseball rat," a player who can't wait to get to the ballpark each day. That work ethic, in addition to an aptitude to take coaching lessons to the mound, has played a big role in his progress this year.
Peralta has come a long way since spring training, when he auditioned for the big league rotation because Greinke had cracked a rib playing basketball. Peralta pressed and tried to do too much, not surprising considering his age and the unexpected situation, allowing 10 runs in 10 innings.
"At his age, he's still a projectable pitcher," Tunnell said. "Earlier in his career, he didn't have the feel for his offspeed pitches that he has now. With any pitcher, there's a transitional period and this has been one of those years for Wily, and he has handled that very well.
"Wily is all business when he goes out there. Every time he steps on the mound, he has the intention of beating you. He has shown the internal growth you like to see in a pitcher."
As it stands now, the Brewers retain club control of the five pitchers who comprise their current rotation through 2012. What that means for Peralta remains to be seen.
"You have to pitch a little more as you move up the ladder, and he has done that," Money said. "The fact that he has fared better shows that he knows you can't just go out there and throw your fastball down the middle.
"If he keeps going like he is now, you're looking at the big leagues next year if the need comes up. From what I've seen of him, he's got the stuff to be a No. 2 or 3 starter up there. He just needs to keep pitching and getting the innings."