Bauer a boost for surging Diamondbacks

Trevor Bauer has been on the fast track to the majors since being drafted No. 3 in 2011. In a week that's already seen the debut of one hotly anticipated

Trevor Bauer has been on the fast track to the majors since being drafted No. 3 in 2011.

In a week that's already seen the debut of one hotly anticipated prospect and the return of another under new colors, the Diamondbacks have trumped both by calling up pitcher Trevor Bauer. The third pick of the 2011 draft out of UCLA, Bauer has rocketed through three levels of the minors and will make his first start against the Braves on Thursday night in Atlanta. The arrival of Bauer, a 21-year-old righty, should give Arizona's battered rotation a boost and help the Diamondbacks climb back into an NL West race that's been reset thanks to the Dodgers' injuries.

After a late-2011 cameo that saw him whiff 15.1 per nine, Bauer entered the year ranked number nine on Baseball America's Top 100 Prospects List, and 11th on Baseball Prospectus' list. Listed at 6-foot-1 and 185 pounds, he isn't an imposing physical specimen. He can pump his fastball up to 97 mph, but it normally sits in the 93-95 range. His deep repertoire also includes an outstanding 12-to-6 curveball, an average-to-above-average slider with a two-plane break, a deceptive, late-breaking changeup, even a splitter and a cutter.

What separates Bauer from most other pitching prospect isn't raw stuff, but an unorthodox style that draws comparisons to Tim Lincecum. His delivery features "an exaggerated stride and lightning-quick arm action," according to BP's Kevin Goldstein, which allows him to generate tremendous torque on his fastball, though he's not as mechanically sound as the Giants two-time Cy Young winner. Observed ESPN's Keith Law, who ranked Bauer 21st in his top 100, "He's patterned his delivery after Tim Lincecum's, getting leverage early, but without 'The Freak's' flexibility or ability to get over his front side."

Additionally, Bauer uses an extreme long-toss regimen between starts. During spring training, he could be seen making throws from foul line to foul line in the outfield, a distance of more than 300 feet. Long-toss is a polarizing subject when it comes to the development of pitching prospects, with some teams feeling that it increases injury risk, and others believing it's an effective method of strengthening arms. Bauer, a cerebral type who has taken great interest in biomechanics, also throws as many as 50 maximum-effort warmup pitches before he enters games. He used his regimen to withstand exceptionally high workloads at UCLA, where he earned both BA's College Player of the Year award and USA Baseball's Golden Spikes Award in 2011.

Bauer has whizzed through three minor league levels in short order, striking out an eye-popping 12.1 hitters per nine in 118 2/3 total innings, including 11.2 per nine in 93 innings at Double-A and Triple-A this year. A tendency to rush his delivery has led to a high walk rate (4.6 per nine) and caused him to burn through his pitch counts quickly; according to Goldstein, he's averaging 101 pitches for every six innings at Triple-A Reno. His groundball rate as a pro is a meager 43 percent, though he has allowed just 0.6 homers per nine overall, with a slight uptick to 0.8 in 44 2/3 innings at hitter-friendly Reno. Given the high altitude of Arizona's Chase Field (at around 1,100 feet above sea level, it's second only to Coors Field), that's something to keep in mind.

The Diamondbacks can use whatever pitching help they can get. A mild shoulder strain that sent Joe Saunders to the disabled list over the weekend opened up a spot for Bauer, but Wednesday's news that Daniel Hudson will need Tommy John surgery creates a longer term vacancy. On the whole, the Arizona rotation ranks 13th in the NL with a 4.21 ERA and 11th with a quality start rate of 53 percent, but remove the ailing Hudson —who enjoyed a breakout 2011 but who had posted a 7.35 ERA and just three quality starts out of nine in 2012 — and they're slightly better than average in both categories despite a tough home park. While staff ace Ian Kennedy has struggled to keep the ball in the yard (1.2 HR/9 en route to a 4.42 ERA), Wade Miley has sparkled via a 2.18 ERA that has as much to do with his ability to limit walks and homers as it does a .256 BABIP; he's quietly emerged as a Rookie of the Year candidate. Saunders and Trevor Cahill have generated groundballs galore while combining for a 3.59 ERA and 17 quality starts in 28 turns. Josh Collmenter, whose straight overhand motion baffled NL hitters last year before wearing out its welcome earlier this spring, will fill one of the two vacancies, though he's expected to return to the bullpen when Saunders returns, assuming Bauer can hold his own.

Stephen Drew

after missing nearly a year