Cardinals co-aces Chris Carpenter and Adam Wainwright have earned their October chops by experiencing postseason highs and surviving postseason lows, but this year those unsteady moments are not so easily dismissed as a blip.

Each one comes with a qualifier.

Both are back in the postseason after extensive surgery, and as the innings start to mount and struggles surface, it's obvious to ask when is a dud just a dud? And when is it a sign of something else, something physical?

It's just not something they will ask themselves.

"It's a fair question to ask. I don't think it's a true question," Carpenter said after his loss in Game 2 of the National League championship series Monday night.

He added later: "Mentally, there's just no way I'm going there. Not now. When you play and do what we do there is no such thing as fatigue and not being capable of doing it. I wouldn't go out there if I wasn't capable of doing it."

Carpenter continued what's become an unsettling stretch for the rotation as the NLCS jets back to St. Louis, tied 1-1.

The San Francisco Giants chased him from the game with a four-run fourth inning on their way to a 7-1 victory at AT&T Park, their first home victory of the postseason. Carpenter is the third consecutive Cardinals starter to fail to get an out in the fifth inning. Only once this postseason have the Cardinals had a starter finish the sixth inning, and that was Kyle Lohse in Game 4 of an NL division series, a game the Cardinals lost.

The last three starters for the Cardinals have combined to pitch less than the bullpen has in their starts. Carpenter, with his four innings Monday night, outpaced Wainwright, who lasted 2 1/3 in Game 5 of the NLDS, and Lance Lynn, who pitched 3 2/3 in Game 1 of the NLCS.

In seven playoff games, the rotation is averaging five innings per start.