If Rocket does make a midseason comeback, great. But in the meantime, they'll have to figure out how to win without him, and they'll proceed with a roster that remained relatively intact following their first World Series appearance.
One of the new faces that could have a tremendous impact is Preston Wilson, who adds a much-needed bat to the middle of the order. He's also a true outfielder who will man left field in a ballpark in which he's had nice success as an opposing player.
The mandate from club owner Drayton McLane is the same as it's been since he bought this club a decade and a half ago: Get to the World Series, and win it. The Astros filled half of his request last year. Their goal this time is to finish the job.
1. Craig Biggio, 2B:
Forty years old and still going strong. Entering his 19th year in an Astros uniform, this sentimental favorite still has plenty of pop in his bat, and he's an institution at second base.
2. Willy Taveras, CF:
There's fast, and then there's Taveras-fast. If he can elevate his game beyond bunt singles and infield hits, this 24-year-old will be a force on the base paths. And he'll be a great table-setter for the middle of the order.
3. Lance Berkman, 1B:
Berkman, a three-time All-Star, is one of the best pure hitters in the league. Healthy and stronger than he was last year, look for the new Astros first baseman to have a huge year.
4. Morgan Ensberg, 3B:
Can he repeat 2005? If Berkman is going to be a force, Ensberg's going to have to be one, too. A solid year will make it impossible for pitchers to get around the heart of the order. Ensberg made great strides last year on both sides of his game, and this year, he could elevate himself to among the league's best.
5. Preston Wilson, LF:
The much-needed bat arrived in January when Wilson hopped on board. He's a power-hitter, an RBI man, and he should fit in well in an up-and-coming lineup.
6. Jason Lane, RF:
Scouts say he has 40-homer potential. The Astros would benefit from that happening sooner than later. Expect a more confident Lane to boost the lineup.
7. Brad Ausmus, C:
Known more for his defense, Ausmus had a terrific second half last year and a great spring. He's fearless and a tremendous veteran presence.
8. Adam Everett, SS:
His defense is sound, his hitting is suspect. Everett saves countless runs with his glove, now it's time to contribute at the plate. He's working on going back to the basics, and after a rough 2005, physically and personally, look for good things from the shortstop.
1. Roy Oswalt, RHP:
Back-to-back 20-win seasons. What more is there to say? This guy's the ace, and he's at his best when he's facing someone else's No. 1. Healthy and entering his prime at 28 years old, look for more greatness from this right-hander.
2. Andy Pettitte, LHP:
He came off major elbow surgery to post the second-lowest ERA in baseball, topped only by teammate Clemens. Pettitte was 14-2 with a 1.56 ERA in his last 20 starts of 2005, from June 20 to Oct. 1, leading the Majors in ERA and wins during that time span. He's a no-doubt Cy Young Award candidate.
3. Brandon Backe, RHP:
If only he had a calendar in his locker that read "October" every day. He's lights-out in the playoffs, and inconsistent the rest of the year. The success of this year's club will rest largely on his win-loss record. He has to step up his game a notch, now that he's the No. 3 starter.
4. Wandy Rodriguez, LHP:
He won 10 games last year, earning a spot in the rotation. It's hard to tell what the young left-hander will do in a full season. If he falters early, he could lose his spot and move to the 'pen.
5. Taylor Buchholz, RHP:
Sixteen months removed from shoulder surgery, Buchholz has regained velocity, strength and confidence. The prize in the 2003 trade that sent Billy Wagner to Philly, Buchholz could be primed for a tremendous rookie year.
The bullpen is the strength of this club, beginning with closer Brad Lidge. His rough postseason took the attention away from what he did during the regular season, which earned him his first All-Star appearance. He still has the wicked slider, the 97-mph fastball and the same confidence he's had since assuming the closer job in the middle of the '04 season. The Astros' tradition of employing a terrific trio in the back end of the bullpen continues this year, with setup man Dan Wheeler returning after a breakout year. Chad Qualls will pitch the seventh but will audition for a setup role. The addition of Trever Miller gives Phil Garner two lefties, which takes the heat off Mike Gallo. Russ Springer brings a veteran presence to a bullpen that has relied on his wisdom for two years.
Knock on wood, the Astros are healthy. Backe has a slight spasm in his back and Springer has battled a rib cage pull for much of the spring, but doctors don't expect either ailment to be alarming.
After Oswalt and Pettitte, what's up with the rotation? The Astros have guarded confidence in Backe, Rodriguez and Buchholz, but inconsistency and inexperience could cause some issues in the back end of the rotation. Backe is stepping into enormous shoes by attempting to take over Clemens' spot as No. 3. Rodriguez won 10 games last year, but his ERA was over 5. The Astros' offense isn't strong enough to be able to overcome that three times a week, and the young unprovens will have to carry their weight. If they don't, the trickle-down effect could be deadly in August and September. The bullpen will have to absorb the load, which will wear it down toward the end of the season. If the Astros are going to get to the postseason and do anything in October, the bullpen will have to be somewhat rested. This starts with the rotation.
ON THE RECORD
"We want to win. It's our goal, our marching orders, from Señor Drayton [McLane]. They're going to have to mature quickly." -- Garner, on the young pitching staff
Alyson Footer is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.