Lee is one of the few players older than 30 who remains on a roster that has gotten significantly younger in the past couple of years. The Astros are rebuilding through youth and player development and hinging their future on up-and-comers like left fielder J.D. Martinez, second baseman Jose Altuve, catcher Jason Castro and pitchers Bud Norris and Jordan Lyles.
"This year, with new ownership and a new [general manager] in place, we have to go out there and play with a fresh mindset," Norris said. "We have to play and have fun and leave it on the field. Our talent is a lot better, too."
Martinez, Altuve and Lyles made their Major League debuts last season and will have more experience under their belts, while Castro is back and healthy after missing all of last year following knee surgery. What's more, the Astros added shortstop Jed Lowrie and starter Kyle Weiland in a trade and have a promising young rotation.
Jeff Luhnow, who's in his first year as GM, knows his club will have a hard time competing in the NL Central, but that doesn't mean the team can't be more competitive on a nightly basis.
"We don't have a lot of margin for error," he said. "We're not expected to be a very competitive team when you look at the National League Central and who we're going to be playing. But we're going to be in every game because we're going to focus on the things that really matter and not give away too many outs or too many runs and hopefully play fundamental, sound baseball. That's really all we can do right now."
The Astros figure to be better offensively after struggling to score runs last season. They upgraded significantly at catcher behind Castro's return and the signing of veteran Chris Snyder. Lowrie, if healthy, should be an upgrade at shortstop, and center fielder Jordan Schafer appears poised for a breakthrough year.
Still, the Astros are banking on Martinez and Altuve to keep developing, third baseman Chris Johnson to rebound and another big RBI year from Lee.
"We're going to see some energy and some enthusiasm and hopefully better-than-expected results," Luhnow said.
But Luhnow said starting pitching is going to be a big determining factor in how the Astros perform, especially early in the season.
They brought in veterans Zach Duke and Livan Hernandez to spring camp, but they were cut after being outpitched by youngsters like Weiland and Lucas Harrell. Then there's ace Wandy Rodriguez, who somehow went 11-11 for a 106-loss team, promising right-hander Norris and left-hander J.A. Happ, who is trying to put a nightmarish 2011 behind him.
"Our rotation, when you compare it to other rotations in the National League, it doesn't stack up on paper, but if our guys can go out there and give five, six innings a night and keep us in the game, I think our bullpen has a chance to help us win some of those close games," Luhnow said.
Norris, who went 6-11 with a 3.77 ERA in 31 starts last year, expects the Astros to continue to grow up.
"We're a year older and a wiser, I guess you could say," he said. "These young guys that came up last year that made some really big strides are ready to go. They got their foot in the water and understand what the big league level is all about, and that helps them with their season and getting prepared for it. The veteran presence we have with Lowrie and Snyder coming over, we've got some guys that can really set the tone, and I think as an overall group we have an understanding that we know we need to get better and leave it all on the field."
The bullpen, which blew 25 of 50 save chances last year, is now anchored by Brett Myers, the 31-year-old veteran who made 66 starts for the Astros over the last two years. Youngster David Carpenter is bursting with potential, and veterans Wilton Lopez and Brandon Lyon know how to pitch.
The Astros' ever-improving farm system could feed more prospects into the Majors this year, a year in which the Houston franchise hopes to begin climbing back to respectability.
"These guys have been trying to compete and perform and we said that at the beginning, that we want to win games and compete and be in every series and every game," Luhnow said. "I think that mentality has produced decent results [in Spring Training] and we expect that to continue into the season."