HOUSTON -- The difference in atmosphere was immediate. The clubhouse suddenly became a happier place, with players bouncing around as they prepared to do their work and throwing out words like "energy" and "enthusiasm" to anyone who would listen.

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Brad Mills, the man the Astros hired as manager to help turn around an 88-loss team, started the arduous process by reaching out to the players in the offseason and quickly changing the toxic atmosphere in the clubhouse on the first day of Spring Training. He promised a renewed energy and organization, he promised to have the players' backs and he promised his team would be prepared.

It didn't take long for Mills to win over the players in the clubhouse during Spring Training, but whether the Astros' new on-field leadership translates into more wins remains the biggest question that will be answered when Houston opens the season against San Francisco on April 5 at Minute Maid Park.

"I like our club and these guys," Mills said.

And the feeling is mutual.

"Clearly, he's made a huge impact to this point, and I think obviously how that transfers into success remains to be seen, as far as wins and losses," slugger Lance Berkman said. "He's been great. He just has a great feel for what he's supposed to be doing and how he can help guys. It's very impressive."

Houston Astros
Projected Opening Day lineup
1 CF Michael Bourn
2 2B Kaz Matsui
3 RF Hunter Pence
4 LF Carlos Lee
5 1B Geoff Blum
6 3B Pedro Feliz
7 C J.R. Towles
8 SS Tommy Manzella
9 P Roy Oswalt
Projected rotation
1 RHP Roy Oswalt
2 LHP Wandy Rodriguez
3 RHP Brett Myers
4 RHP Bud Norris
5 RHP Felipe Paulino
Projected bullpen
CL RHP Matt Lindstrom
SU RHP Brandon Lyon
MI LHP Tim Byrdak
MI RHP Jeff Fulchino
MI RHP Sammy Gervacio
MI RHP Brian Moehler
MI RHP Chris Sampson
Full 25-man roster | Depth chart
It's no secret former manager Cecil Cooper wasn't popular among the players, who were frustrated by some of his on-field strategies as much as what they perceived was a lack of communication. Mills, who spent the previous six years as bench coach of the Boston Red Sox, came in with a take-charge approach and an open-door policy with his players.

"I know that teams have a better chance of winning if the atmosphere is right and they have a good leader to follow," veteran infielder Geoff Blum said. "He's done a good job of earning our respect, and it's obvious in the way we're playing the excitement of us showing up every day."

Mills isn't the only new face the Astros are counting on this year. Mills brought in former Toronto pitching coach Brad Arnsberg help improve a staff that ranked 13th in the National League in ERA (4.54) last year. The club added a workhorse starter in Brett Myers and added Matt Lindstrom and Brandon Lyon to the back of the bullpen.

Houston lost All-Star shortstop Miguel Tejada to free agency, but signed third baseman Pedro Feliz and gave the starting shortstop job to rookie Tommy Manzella to improve the infield defense.

But as much as Houston will be counting on its newcomers, it can't contend without big seasons from some familiar faces. Berkman and ace Roy Oswalt, coming off subpar seasons during which they battled injuries, will need to produce. Left fielder Carlos Lee will be asked to contribute once again.

"The concern is health," All-Star right fielder Hunter Pence said. "Berkman had knee surgery, and we need that to heal up. He's going to be a key for our success, and the pitching's got to stay as healthy as possible. You know there are injuries and things you have to battle through, but the main thing is making sure we're prepared and coming in ready to play."

Berkman, who had arthroscopic knee surgery on March 13, is the longest-tenured member of the team and has seen the highs and lows of a decade in Houston. The club is not considered a favorite to contend in the National League Central, and Berkman says people are selling the team short.

"I feel like we're going to be very competitive, providing we stay healthy and guys perform like they have in the past, which is not an unreasonable expectation," Berkman said. "That could possibly happen, and if that happens, I don't see why we wouldn't be neck-and-neck with the front runners in the division. I really think we can win this division."

Those in the clubhouse and front office might be the only people who think the Astros are capable of contending in the division, but that's just fine with the players.

"Having people write us off would be fine with us," Blum said. "We're just going to go out and play our game, and that's all we can do. Fortunately, we don't have to worry about the media attention or expectations and things like that -- just the expectations we have on ourselves. We're looking forward to a fun season, if we can keep everybody healthy."