With Sunday's Game 4 of the National League Division Series threatening to go 19 or 20 innings, Andy Pettitte dragged himself off his couch at home and brought himself back to Minute Maid Park, "just to give them an option."

Pettitte, the Houston Astros' veteran left-hander, had been sent home earlier in the day with headaches and severe nausea, and he slept through the first seven innings of the Astros' 7-6 victory over the Atlanta Braves, a win that took 18 innings. He began calling team officials in the ninth inning, wondering if he might be needed, and started playing catch at home. When Roger Clemens, a usual starter, entered in the 16th, Pettitte was back at the ballpark, limbering up. But once Chris Burke hit the game-winning homer, Pettitte "just threw my street clothes on and left, so that was my day."

Pettitte participated in Tuesday's workout at Busch Stadium, and he declared himself healthy enough to start Wednesday's first game of the National League Championship Series against the St. Louis Cardinals.

"I'm feeling better, a lot better," he said.

Pettitte's availability means the Astros have their three primary starters lined up just as they would want them. Pettitte will be followed by Roy Oswalt in Game 2 and Clemens in Game 3. Brandon Backe will likely start Game 4, leaving Pettitte, Oswalt and Clemens for Games 5-7, if necessary.

A 'Positive' Workout for Mulder

The Cardinals' rotation gained some clarity as well Tuesday. Lefty Mark Mulder threw on the side, his first action since taking a line drive off his left biceps during his win over the San Diego Padres last week. Cardinals Manager Tony La Russa said he would wait until Wednesday to say for sure whether Mulder will start Game 2 on Thursday, but he characterized the session as "positive."

"Every day it's been better," La Russa said.

Whether Mulder throws Game 2 or not, right-hander Matt Morris is slated to pitch Game 3 on Saturday in Houston. La Russa said he has decided on his Game 4 starter, but he hasn't yet told Jeff Suppan (16-10, 3.57 ERA) or Jason Marquis (13-14, 4.13), so he kept the decision to himself.

Clemens Reflects on His Mother

Clemens said he still frequently thinks of his mother, Bess, when he pitches, and that is especially true in the postseason. "She still lives within me," Clemens said. "I've got a job to do, but I know she'll be there to help me do it." Bess Clemens-Booher died Sept. 14 of complications from emphysema. Clemens pitched and beat the Florida Marlins that night. . . . Cardinals reliever Ray King traveled to Tennessee for the funeral of his father, but is expected to be available for the entire NLCS. King did not pitch in the Cardinals' sweep of the Padres.