PHOENIX -- Runnin' Ron Roenicke took the floor Friday morning and told his team he wants to be extra aggressive on the bases once the Brewers' Cactus League games begin Sunday.

Roenicke, entering his second season as Milwaukee's manager, employed a similarly aggressive approach in 2011 Spring Training games but it faded in the regular season, when the Brewers led the National League in home runs and ranked 12th in stolen bases.

"I'd like to be a little more creative in what we do," Roenicke said. "It's all about how you manufacture runs without Prince [Fielder] in the lineup. We need to do some things to maybe make up for his loss."

Fielder signed with the Tigers in January. Roenicke is not just talking about covering that absence with stolen bases, but with aggressive decisions on the bases; going from first to third, scoring from second base when some teams might hold up. It's a philosophy that Roenicke preached in his very first appearance as Brewers manager in November 2010, when he said he believes that aggressive teams force mistakes from their opponents.

The Brewers are not blessed with a slew of speed demons, though left fielder Ryan Braun and center fielders Carlos Gomez and Nyjer Morgan are stolen base threats. Time will tell whether leadoff man Rickie Weeks is able to run on his still-healing left ankle, which he sprained last July. Right fielder Corey Hart was once a runner, though he has gotten away from that facet of his game in recent years, especially under former manager Ken Macha, who preferred a station-to-station approach. Roenicke considered Hart one player who will run more in 2012.

"We're going to try to do it, and we'll see how it goes," Roenicke said. "If we're running into too many outs, and I don't like what's going on, then we'll rein them back a little bit. But I think Spring Training is a good test for them to see what they can do, how far we can go with being aggressive."

That test begins Sunday at Maryvale Baseball Park, where the Brewers will host a Giants split squad. It's the first of Milwaukee's 35 Cactus League games, a slate that runs through April 3-4 with two matchups against the D-backs at Chase Field.

It's an unofficial beginning to the Brewers' defense of the National League Central, a crown they won last season by winning a franchise-record 96 games. Most of the team is back, including all five starting pitchers and back-end relievers Francisco Rodriguez and John Axford. The high-profile newcomers are on the left side of the infield, where Aramis Ramirez will man third base and veteran Alex Gonzalez will be the Brewers' fourth shortstop in as many seasons. In the outfield, the notable newcomer is Norichika Aoki, a three-time Japanese batting champion who will see if his game plays in the U.S.

The Brewers begin with back-to-back games against the Giants, including a Monday night matchup in Scottsdale, Ariz., to air in Milwaukee on MLB Network at 8:30 p.m. CT. That game is also available online via MLB.TV.

Sunday's afternoon opener will air in Wisconsin on the Brewers Radio Network and online via MLB.com's Gameday Audio. Left-hander Madison Bumgarner is scheduled to start for the Giants. Starters Randy Wolf and Zack Greinke will work for Milwaukee, and closer Axford said he's also slated to pitch.

Wolf is scheduled to start and Greinke will follow. How did they set the order?

"That's just veteran, I guess," Roenicke said. "I guess [Wolf] has got a little more pull than Zack has."

In truth, Wolf requested the start and Greinke didn't mind the rare relief outing. Left-hander Chris Narveson is scheduled to start Monday night against the Giants and Yovani Gallardo will work Tuesday against the A's.

The team's other starter, Shaun Marcum, is not scheduled to debut until the following week, a move to limit his innings after last year's heavy workload.

Expect the pitchers to have the early upper hand, Weeks said.

"You're never really ready for the first day," he said. "But I'm sure everybody is anxious to get these games going, get back in the swing of things, but you probably need a couple of games to get used to where you stand in the box, used to seeing a pitcher live. That's probably the hardest part. You can do all the live [batting practice] you want, but as soon as that cage comes away, it's a totally different story."

Said Morgan: "You get to set your eyes. You basically hone for skills for the upcoming grind, but I've never been a great Spring Training player. The last week and a half, that's when [his numbers] start going up. If you have a good approach, people see that."

For other players in camp, the numbers are more important. The Brewers have two unclaimed spots in the bullpen and two on the bench, with a number of candidates for both areas.

Among the openings are for backup infielders, and veteran Cesar Izturis is a leading contender because he's a natural shortstop. Even with more than a decade of Major League service, he feel he needs to prove something in camp.

"Of course," Izturis said. "Especially in this game, when you learn something every day. When you come to a new organization, you want to open eyes, even though they know what I can do. It's a new team, new people, and these games are very important."

The Brewers had two extra workout days this year between the first full-squad workout and the start of Cactus League play. That means players are itching to see some enemy players.

"Guys are in shape, and they're wanting to play now," Roenicke said.