Carlos Beltran hits a two-run home run in Game 1 against the Giants. (Christian Petersen/GETTY IMAGES)

Carlos Beltran’s problematic left knee, injured as he ran out a groundball in the first inning of Game 3 of the National League Championship Series, remained painful enough that he did not play for the St. Louis Cardinals in their Game 4 win on Thursday night. What that means as the Cardinals go forward remained unclear.

“It was painful,” Beltran said before the Cardinals faced the San Francisco Giants in Game 4. “There’s no doubt. In order for me to take myself out of the game, it has to be painful. But the good thing is I wake up feeling a little bit better today, and hopefully tomorrow I wake up feeling a little bit better.”

Beltran’s absence, even for a game, is of concern given his postseason résumé. He is the all-time leader in postseason slugging percentage (.830) and postseason on-base-plus-slugging (1.316). Matt Carpenter filled in for Beltran in Game 3 and hit a two-run homer that proved to be the difference. Carpenter was in Beltran’s second spot in the order Thursday, but he played first base with Allen Craig moving to Beltran’s spot in right field.

Beltran moved with a limp up and down the dugout stairs prior to Game 4. He said he took dry swings — with no ball involved — and planned to hit in the cage before the game. Manager Mike Matheny said Beltran would have been available as a pinch hitter — “a nice weapon to have,” Matheny said — but the major concern is getting him well enough to play the outfield.

Beltran, a switch hitter, is 12 for 30 with five doubles, three homers and a .486 on-base percentage in eight playoff games this year. But the Cardinals do not appear to be considering replacing him on the roster — which would take him out of the World Series as well — and remain hopeful he could start Friday’s Game 5.

Another chance for Zito

By some measures, Barry Zito would seem an obvious choice to start Game 5 of the NLCS for the Giants. In a comeback season, he won his last five starts — posting a 2.35 ERA in that span — en route to a 15-8 record.

But this was Zito’s first winning season since joining the Giants in 2007, and he lasted only 22 / 3 innings in his only start this postseason, Game 4 of San Francisco’s division series against Cincinnati.

“I’m capable of throwing all my pitches for strikes and keeping guys off-balance,” Zito said.

Zito, 34, is under contract for $20 million in 2013 — the last guaranteed season of the seven-year, $126 million deal he signed with the Giants. (There is a vesting, club option for 2014, and the Giants can buy him out for $7 million more.) But this is just the second postseason start he’ll make for San Francisco.

“He’s had a good year for us,” Manager Bruce Bochy said. “He’s won some big games. His command, his overall stuff has been really good and consistent this year.”

METS: Cy Young candidate R.A. Dickey had abdominal surgery and is expected to be ready for spring training. The team said William Meyers performed the operation Thursday in Philadelphia to repair a core muscle injury.

— Associated Press