GOODYEAR, Ariz. -- The U.S. Green Building Council announced Monday that Miller Park became the first stadium with a retractable roof and the third Major League Baseball stadium to achieve the highest certification for environmental sustainability.

The stadium has been LEED (Leadership in Energy and Environmental Design) certified in the category of "existing building operations and maintenance." The honor recognizes the Brewers and their partners in running the 11-year-old stadium, led by facility manager Johnson Controls, Inc., which managed the LEED process at Miller Park.

AT&T Park in San Francisco and Target Field in Minneapolis are the only other Major League venues to earn the same certification.

"It is a challenge to achieve the designation in an existing building of this size and type, but we have all been focused on the end goal," Brewers vice president of finance and administration Bob Quinn said in a statement. "Earning this designation means that we have significantly improved our sustainability and energy efficiency, and the benefits extend to the organization, our fans, partners, and the environment."

LEED-certified buildings are designed to lower operating costs, reduce waste sent to landfills, conserve energy and water, reduce greenhouse gas emissions and be healthier and safer for occupants.

The Brewers said they had reduced by 35 percent the amount of waste sent to landfills since the start of 2010. About 10 tons of waste is now recycled after each game. The Brewers are also saving thanks to the new scoreboard installed for last season, which uses 49 percent less energy than its predecessor.

"While we are honored to have achieved this designation, our commitment will continue in 2012 and beyond," Brewers COO Rick Schlesinger said in the club's statement.

Hart inching closer to playing Minors games

GOODYEAR, Ariz. -- Brewers right fielder Corey Hart could be playing Minor League games by Wednesday, but it appears increasingly likely that he will miss the first series or two of the regular season.

Still, manager Ron Roenicke would not rule out Hart for the Opening Day lineup. On Monday he spoke to reporters as Hart prepared to try sliding drills for the first time since his March 6 right knee surgery.

"[Wednesday] is not set," Roenicke said. "We'll see how he does. ... We'll see if he goes at it a little but harder today, and then if everything goes right, then Wednesday is the day that we could give him some at-bats on the Minor League side."

Spring Training
• Spring Training schedule

Hart would get about three at-bats on the first day and will not play the outfield, but could quickly ramp-up. Minor League Spring Training games are run loosely, and Hart could eventually lead off every inning.

Because he won't appear in Cactus League games, the Brewers could backdate a season-opening stint on the 15-day disabled list to March 26. In that scenario, Hart could be active for April 10, the fifth game of the regular season at Chicago's Wrigley Field. But cold weather there may delay Hart's arrival until April 13 in Atlanta.

The schedule remains under discussion. Roenicke was not prepared to rule out Opening Day.

"It really depends on Corey and how fast he comes along," he said. "We've got to get him to nine innings. ... We'll just see how that comes along. The swelling in his knee isn't getting worse, so that's good with all the activity he is doing.

"if he is locked-in right away, he is going to have a chance to be ready for Opening Day. Versus, if he's scuffling, no, he won't be ready for Opening Day."

Roenicke close to setting Brewers' rotation

GOODYEAR, Ariz. -- Brewers manager Ron Roenicke planned to chat with some of his starting pitchers on Monday about the order they'll pitch to start the regular season, meaning he was very close to publicly declaring Yovani Gallardo the Opening Day starter.

The order is plain to see.

Gallardo will start on Tuesday against the Royals and April 1 in the Maryvale Baseball Park finale, putting him in line to pitch April 6 against the Cardinals at Miller Park. It would be Gallardo's third consecutive Opening Day assignment.

"He's huge for our staff," Roenicke said. "He's a workhorse, and it's a productive workhorse. It would be tough to get along without him."

Zack Greinke pitches the next day and Randy Wolf after that, lining them up to pitch the remaining two games of the opening series against the Cardinals. Shaun Marcum follows and then Chris Narveson, putting them in line for regular season debuts against the Cubs at Wrigley Field on April 9 and 10.

"They pretty much know [the order]," Roenicke said. "And I've told them, we're not holding anything back. We just want to see that everybody is healthy."

Marcum, a right-hander, would break up the left-handers Wolf and Narveson. Marcum started Sunday's game against the Dodgers and appears to have overcome a bout of shoulder stiffness.

Roenicke said club officials discussed Monday morning the setting of Marcum's next start. He could either pitch Friday's Cactus League game against the Dodgers, or pitch in Minor League camp if the club opts to preserve the option of backdating a stint on the 15-day disabled list.

Marcum will throw his between-starts bullpen session on Tuesday. The venue of his next start will be determined after that.

"I think Shaun likes to be challenged, and to pitch him in a Major League game, I think, challenges him more," Roenicke said. "The thing that we risk is, if there did happen to be a setback, then we lose him for 15 days, but we don't expect that to happen. He feels great. We like what we saw."

Last call

• Alex Gonzalez sat out a second straight game Monday to rest a bruised right heel.

"We're being cautious with him, just this time in the spring," manager Ron Roenicke said. "He's played a lot. I don't want him to have this thing aggravated by continuing to play. So he'll have today off, and hopefully [Tuesday] he'll be fine."

• Carlos Gomez missed a second straight day with an illness. He resumed workouts on Monday morning and could also play Tuesday, according to Roencike.

• Pitchers Daniel Meadows and Josh Butler were returned to the Minor Leagues on Monday, leaving 36 players -- 16 pitchers, four catchers, nine infielders and seven outfielders -- active in Major League camp. Both Meadows and Butler were non-roster invitees and could start the year at Triple-A Nashville, Meadows in the bullpen and Butler in the rotation.