HOUSTON -- There are no easy fixes or solutions for the Astros, a team seemingly caught between a youth movement and a roster full of veteran players who likely wouldn't want to be part of a rebuilding mode.

Thirtysomething former All-Stars Lance Berkman, Roy Oswalt and Carlos Lee -- who combine to make more than half of the team's $93 million payroll this year -- would love nothing more than to get the Astros back to the World Series and finish their careers as October heroes.

But at roughly the one-quarter mark of the 2010 season, the Astros are in last place in the National League Central and need a drastic turnaround to reach the playoffs for the first time since 2005. Should they push forward behind Berkman, Oswalt, Lee and other veterans, such as Brett Myers and Geoff Blum, or start a youth infusion?

The Astros may not have much of a choice, considering the fact that most of their top Minor League talent is in Double-A and below, and Berkman, Oswalt and Lee all have no-trade clauses. Berkman and Oswalt have said they would be willing to waive their clauses if the situation were right, but trades at this point seem unlikely.

"If at some point in time we have a way to better the club, whether we're playing great or poorly, that's always the objective," general manager Ed Wade said. "But for the time being, we have to keep the faith in the guys that have done it in the past and know they're going to do it again."

Berkman has a club option for next year, Oswalt is under contract through 2011, with a club option for 2012, and Lee is signed through 2012. Berkman, the longest-tenured player on the team, created a buzz when he said last month he'd agree to a trade if the Astros could get some young talent in return to inject into the Minor League system.

"That was the motivation behind the comments I made earlier that everybody made such a big deal about, and as an organization, that's certainly not the place you want to be," Berkman said. "You don't want to be devoid of young and promising prospects, and at the same time battling age at the Major League level. That's not where anyone wants to be.

"That having been said, I still like this team. I still think it's a good team. I don't know how good it is, but I certainly think it's better than what we've shown so far."

Wade, recognizing that some changes had to be made, stirred the straw following Wednesday's win over Colorado and placed veteran second baseman Kazuo Matsui on waivers for the purpose of giving him his unconditional release. The club purchased the contract of 25-year-old infielder Oswaldo Navarro, who was signed as a Minor League free agent last year. He'll back up second baseman Jeff Keppinger and rookie shortstop Tommy Manzella, who represents the first wave in what the Astros hope will become an infusion of young talent at the Major League level.

The majority of the Astros' Triple-A roster is made up of players acquired from other organizations, with some of the top prospects starting to bubble up to Double-A. One exception is catcher Jason Castro, the club's No. 1 pick in 2008. Castro began the year at Triple-A Round Rock and could be called upon at some point, but the consensus is that he's not quite ready.

"We need to give Castro more time at Triple-A, but all reports are this kid has a chance to be a really good player at the big league level," Wade said.

Houston's biggest struggle this season has been offense, primarily because middle-of-the-order sluggers Berkman, Lee and Hunter Pence haven't produced to their past standards. The Astros don't have any bats at Triple-A that could help fill that need, so they have no choice but to let those three ride out their slumps.

"We need to get consistent, and there are signs it's beginning to happen," Wade said. "Carlos' game [on Tuesday] night ... was a huge step in the right direction. It's only one game, but you take that one game and the sweep against the Cardinals, and you take the way Hunter has begun to swing the bat at this point in time, and Lance's average is climbing.

"I don't want to put too much of it on one particular subset of players, but a lot of it depends on what those three guys do for us, and they're beginning to show signs. We need to continue to do what we're doing right now. There are no replacement 3-4-5 hitters at Round Rock, and we need the guys who are here in the middle to do what they are capable of doing."

Still, there's reason to be optimistic about the Minors.

Right-hander Jordan Lyles, 19, threw a four-hit complete game on Tuesday at Corpus Christi to lower his ERA to 2.29. His teammates T.J. Steele and Jon Gaston -- outfielders drafted in 2008 out of Arizona -- have high ceilings. Left-hander Dallas Keuchel and right-hander Ross Seaton lead a promising group of pitchers at high Class A Lexington.

Tal Smith, the Astros' president of baseball operations, recently returned from a trip to low Class A Lexington and came away impressed with the defensive play of Jiovanni Mier, a shortstop picked in the first round last year. Outfielder J.D. Martinez (.348) and first baseman Kody Hinze (.336, 12 homers, 43 RBIs) have also began to turn some heads at Lexington.

With the exception of Castro and third baseman Chris Johnson at Triple-A, the best talent in the Minors could be a couple of years away, but Wade is confident that the steady stream of young talent will begin trickling to the Majors at some point.

Whether Berkman, Lee and Oswalt are around to see it remains to be seen.

"We're in a society where instant gratification is sort of the norm," Wade said. "It's got to happen now, and it's sort of the quote-unquote 'do something' mentality. I would rather us try to make smart decisions. Sometimes the smart decisions you make is, 'Hey, suck it up for a while.'

"That sends a message that we have faith and confidence in the rest of the guys here, but there is also accountability, and you need to step up and take advantage of the opportunities they're getting, whether veteran players or younger players. It's going to come down to the core guys here to step up and do what we know they're capable of doing."