This is the first of a series of stories that will take you Around the Horn with the 2013 Milwaukee Brewers. Up first, the facet of the team sure to stir the most discussion in spring camp: The starting rotation.

PHOENIX -- Yovani Gallardo is a humble right-hander who grew up in Fort Worth, Texas, and has always seemed most comfortable when sharing the spotlight.

Ben Sheets led Milwaukee's starting rotation when Gallardo, the most promising Brewers pitching prospect since Sheets himself arrived six years earlier, joined the club in the Majors in 2007. It was CC Sabathia's rotation in 2008, even though it was Gallardo starting the Brewers' first postseason game in 26 years. In 2009 and 2010, the rest of the starting rotation's struggles overshadowed Gallardo's quietly solid seasons. And in '11 and '12, Gallardo shared top billing with Zack Greinke.

Now comes 2013, and Gallardo is far and away Milwaukee's most accomplished starter, and is more than ever being counted on for the sort of season forecast by his former catcher, Jason Kendall, who predicted Gallardo would win multiple Cy Young Awards.

Gallardo doesn't mind being the clear No. 1.

"It's one of those things that everyone wants at some point in their careers," he said. "Being here for a while now, I've seen Sheets, CC, Greinke, all of those guys, come in and out. Now, here I am. I might be the oldest one here.

"It just means a little more responsibility."

Gallardo, who'll turn 27 on Feb. 27, is not the oldest, but definitely the most experienced.

After making an unsuccessful run at free agent Ryan Dempster, who signed with Boston, the Brewers decided to go with a corps of young starters -- a bold call by general manager Doug Melvin considering the team has a contender-caliber offense. Gallardo is in line for his fourth straight Opening Day start and is the unquestioned staff ace. After that, every candidate is equal parts promise and risk.

Right-hander Marco Estrada is being counted on as the Brewers' No. 2 starter after posting a 3.64 ERA last season and the third-best ratio of strikeouts to walks (4.93) among National League pitchers who worked at least 100 innings. But he will turn 30 in July, and has only 32 Major League starts, 23 last season.

Left-hander Chris Narveson has a longer track record (95 appearances, 63 starts in the Majors), and logged double-digit win totals in 2010 and 2011. But he missed the final five months of 2012 after undergoing major shoulder surgery.

The rest of the candidates are unproven. Right-handers Wily Peralta and Mark Rogers have long held prospect status and showed why during solid stints last September. But Peralta, MLB.com's top Brewers prospect, has a history of command issues and Rogers a history of injuries. Another right-hander, Mike Fiers, was so good last May, June and July that the Brewers began campaigning for him as an NL Rookie of the Year candidate. But he began to fade in August, and had a 7.09 ERA in September, prompting questions of whether the rest of the league had caught on to Fiers.

One of those three younger pitchers could end up in the bullpen as a reserve starter. Triple-A Nashville will likely be led by Tyler Thornburg, No. 2 on MLB.com's Brewers prospects list, and Hiram Burgos, the organization's 2012 Minor League pitcher of the year.

Peralta is 23, Thornburg is 24 and Burgos is 25. If any of them crack the starting rotation, it would mark a significant shift from last season when, according to Baseball-Reference.com, the Brewers and Pirates tied for the fewest starts by pitchers 25 or younger -- nine apiece. The Oakland A's led baseball with 101.

Oakland also won the American League West.

"We saw what the [young] guys did last year for us," Gallardo said, referring to the Brewers' late-season surge. "They stepped up. They're aggressive. They went up there and attacked whoever was hitting. That's good. They pitched their game and [showed] we could pretty much compete with anybody."

Gallardo has done his part in recent years. A second-round Draft pick in 2004, he debuted midway through the 2007 season and has never finished with an ERA above 3.84. He was limited to four regular-season starts in 2008 by a freak knee injury. But Gallardo had surgery, made it back in time for that year's playoffs and then signed a five-year, $30.1 million contract extension in April 2010 that made him Brewers property through 2014 and includes an option for 2015. Since then, he has topped 30 starts and 200 strikeouts every season. Gallardo owns four of the nine 200-strikeout seasons in franchise history.

Yet there is a vocal segment of the Brewers' fan base that does not consider Gallardo an ace. They point to the fact he has only four career complete games, and none in his last 64 starts. He led the NL in total pitches last season (3,480), yet pitched into the eighth inning only twice.

He may throw even more pitches in 2013 because Gallardo is Team Mexico's top arm in the World Baseball Classic. With that event in mind, he reported early to Maryvale Baseball Park to make sure his arm is in shape.

"I really wanted to do it," said Gallardo, who missed the Classic in 2009 because he was coming off knee surgery. "Obviously, you hear things about guys getting hurt and things like that because it's early in the season. But even at this time last year, I had thoughts about participating. I had a mindset ready to start things a little earlier.

"Honestly, I think it will help prepare me, get me ready quicker for Opening Day than Spring Training. The games are more competitive. You're actually playing for something."

The Brewers' Opening Day is April 1 at 1:10 p.m. against the Rockies at Miller Park.