Despite their fantastic finishes in recent seasons, common sense tells you the Astros face way too many obstacles to get up off the mat one more time, as they did in 2004 en route to the National League Championship Series, or 2005 on the way to the World Series and again last year, when they were eliminated from playoff consideration on the final weekend of the regular season.
There's no way you'd think this flawed team can overcome so many concerns, like a pitching staff that ranks 14th in the league in ERA, an offense that has outscored just eight of Major League Baseball's 30 teams and a bullpen that ranks next to last in the league in ERA.
And yet, watching Roy Oswalt and the Astros finish off a sweep of the Cubs with a thorough 8-2 victory over Carlos Zambrano on Wednesday night at Minute Maid Park, you are reminded of the words of a former Astros bench coach, Yogi Berra, who said, "It's never over until it's over."
Their triumph left the Astros 8 1/2 games behind first place Milwaukee in the National League Central Division, the closest Houston has been since June 17. Fourteen games out on July 18, the Astros have shaved 5 1/2 games off that lead in three weeks.
The Cubs are one game behind the Brewers, and third-place St. Louis, another team written off by many people, is just six games behind Milwaukee.
The Astros stood pat at the trade deadline for two reasons: attractive upgrades weren't available, and they believe this team will have a shot if it can get within five or six games of the lead by Sept. 1.
That seemed highly unlikely as recently as a week ago. Now it seems plausible, though the Astros are treating it no differently than yesterday's win.
"It's a step," Astros manager Phil Garner said. "We hope that it gives us a little more momentum with Milwaukee coming in here, but it's just a step. The reason the sweep is so important, it's a two-game swing. But more importantly, we've got to continue our march to .500, that's going to be key for us."
The Astros roughed up Carlos Zambrano -- who came in having allowed three runs or fewer in 11 consecutive starts and two runs or fewer in 10 of those -- for seven runs on eight hits in 5 2/3 innings. The Astros hit for the cycle against the Cubs ace before the third inning was over.
There have been other indications that could bode well for Houston's September possibilities. The Astros, 17-7 in their last 24 home games and 20-11 in their last 31 at Minute Maid Park, play most of their remaining games at home. They swept the Cubs in Houston for the first time since Sept. 10-12, 1999, in a series that was played at the Astrodome.
They outscored Chicago 15-5 and held the Cubs hitters to an .060 (2-for-33) batting average with runners in scoring position. The Astros have hit at least one home run in 11 consecutive games.
Lance Berkman, who hit a mammoth shot to left-center off Zambrano, appears to be heating up. Carlos Lee, tied for second in the NL with 92 RBIs, is hitting .455 in his last eight games.
Woody Williams picked up a win in the second game of the series, and Oswalt followed with his 12th victory. If those two can continue that Texas two-step and lefty Wandy Rodriguez can somehow duplicate his home dominance (1.69) on the road, this race could get really interesting.
Granted, it's nearly as many ifs as Lee has RBIs, but this team has been here before.
Last year, after 114 games, the Astros were in third place, six games behind the Cardinals, who were about to begin a slide. This year, the Brewers, who begin a three-game series here Friday night, have lost eight of their last 11.
The inability of either the Brewers or the Cubs to pull away from the pack has made this a race that clearly won't be decided in August. Houston still has a combined 15 games left with the Brewers and Cubs. And don't forget the Cardinals.
St. Louis, like Houston, has been through pennant-race pressure before.
Perhaps that's why Berkman, when asked about the possible momentum boost from sweeping the Cubs, kept it in perspective.
"I think we're down to single digits out of first place. We've certainly been here before, so a nice little 20-game winning streak and we'll be right back in it," Berkman cracked.
Jim Molony is a writer for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.