Their opponent is banged up and starting a pitcher who hasn't pitched since Sept. 25.
In many ways, it may look like the Astros are sitting pretty, just don't try to tell them they are in the driver's seat.
As far as the Astros are concerned, Game 4 of the NLCS on Sunday figures to be another tough task against a team they respect, the NL Central Division champion Cardinals and right-hander Jeff Suppan.
"[The 2-1 lead] is huge, but we still have to take advantage of it, and it isn't going to be easy," said Houston's Mike Lamb, who contributed a two-run homer to help the Astros win Game 3. "That is a very dangerous team over in that other clubhouse, and they're not going to just go away.
"[Getting ahead] 3-1 would be command at this point, but they're too good of a team to relax and even if we're up 3-1, we can't relax. They've got [Albert] Pujols over there and Larry Walker. The problem for us this year has been scoring runs and if we continue to [score runs], I like our chances."
Suppan is well rested and ready to go for St. Louis. In his last start, he pitched eight scoreless innings in a 2-0 victory over Milwaukee. Suppan is 4-0 with a 1.67 ERA in his last six starts and went 7-3 with a 2.78 ERA after the All-Star break. He has been preparing himself for this vital start.
"Mentally, I think the key is staying prepared in a number of ways," Suppan said. "One, just visualizing that you're out there and, when you're watching the game, seeing the pitch that you would throw and just trying to put yourself in the situation, because it has been awhile since I've thrown."
Houston will start right-hander Brandon Backe, who has historically been much better at Minute Maid Park than on the road. In his last start, however, he lasted only 4 2/3 innings against Atlanta in Game 4 of the NLDS. The Astros went on to win that game, 7-6, in 18 innings to advance to the NLCS.
Last year, Backe limited St. Louis to three baserunners over eight innings in Game 5 of the NLCS.
"It's just a big confidence boost," Backe said. "Just the success that I had alone in the playoffs helps me relax, helps me just basically know that I'm not going to let the playoff atmosphere affect me in any way. I've been through it before, and I've also succeeded. So really it just helps me out having gone through that experience last year."
The Cardinals didn't have outfielder Reggie Sanders, who sat out Game 3 following his back injury in Game 2. They also might be without third baseman Abraham Nunez, who collided with Jason Lane in the sixth inning and had to be helped off the field.
"He got hit on the area just above the knee," St. Louis manager Tony La Russa said. "I don't think he twisted it, so it's just a bruise. We'll see how he feels [Sunday]."
Starting third baseman Scott Rolen is out for the season.
"Being up 2-1 in a seven-game series against St. Louis means nothing," Astros catcher Brad Ausmus said. "We were up 3-2 against them last year and lost."
Last year, the Cardinals won the NLCS in seven games as the home team won every game.
"We're up a game in the series and we're not going to take that for granted," Astros manager Phil Garner said. "We're not going to take any players for granted. If they are banged up, it might limit their options a little bit, but still, [John] Mabry is a good hitter and I won't like seeing him up there in the ninth inning or seeing him in the game if Nunez can't play.
"Sanders I'm sure is going to be playing, and you know what Walker can do. He may not be 100 percent, but still he's a threat. I don't see it as a disadvantage. It may not be exactly as they would like to have it, but I can't tell you how much we respect their team."
First pitched is scheduled for 4:45 p.m. ET.
Jim Molony is a national writer for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.