Karros Powers Dodgers to Win : Tuesday’s game: He hits game-winning homer for second day in a row. L.A. pulls within two games of Colorado.

The Dodgers are trying to buy time, staving off their critical decision whether to trade for a third baseman or stand pat during the pennant stretch.

They’ll candidly tell you that there’s not quite a sense of urgency.

For that, they can thank first baseman Eric Karros, who once again flourished in the hero’s role Tuesday night, hitting the game-winning homer in the Dodgers’ 4-3 comeback victory over the St. Louis Cardinals.

“I guess the key,” said Todd Worrell, who produced his 21st save, “is to get Eric in there with the game tied and the last at-bat. He kind of likes that.”

The paid crowd of 33,602 at Dodger Stadium, which heard all about Karros’ game-winning homer Monday in the 12th inning against the Giants in San Francisco, was able to witness the latest heroics in person.

The Dodgers, trailing, 3-0, in the fifth inning and in danger of becoming the first team in two years to lose to Cardinal starter Donovan Osborne, tied the game in the seventh and set the stage for Karros in the eighth.

Karros, who grounded into two double plays his first two at-bats before driving in a run in the sixth inning, led off the eighth. He watched slider after slider from reliever Jeff Parrett, and then on a 2-and-2 pitch, Parrett tried to fool him with a split-fingered fastball.

Karros sent it into the left-field seats for his second homer in five at-bats.

“It’s a great feeling to produce again,” Karros said, “but you don’t want to keep having games like this. These games start to wear on you. I’d prefer to have those games where you lead from the first inning on.”

The victory enabled the Dodgers (50-45) to cut the Colorado Rockies’ lead to two games in the National League West.

“We have to win games like this,” Worrell said. “We can’t afford to let any more opportunities slide by, especially with Colorado on the road and out of that band-box stadium they play in. We’ve got to take advantage of it, and kick ourselves to take advantage.”

The Dodgers, who still have five more games against the Cardinals (39-56) and have only one game with a team more than one game above .500 until they meet the Rockies again Sept. 25, may take in consideration their patsy schedule before finalizing their key decision.

Do they gamble that third baseman Tim Wallach’s back stays sound for the rest of the season? Or do they trade away valuable prospects to acquire a third baseman?

Wallach, who received a cortisone shot in his lower back Tuesday after being examined by Dr. Robert Watkins, has played only two innings in the last seven games. The Dodgers were relieved to discover that Wallach has no nerve damage and were told by Watkins that Wallach should return to the lineup Saturday.

“We obviously can’t go on and on,” said Fred Claire, Dodger executive vice president, “but I was encouraged by the report. From my position, it was very encouraging. He should be able to do everything in [three] days.

“I want to give Tim every chance to see if he’s capable of playing every day.”

There lies the rub. Wallach, 38, who’s playing this season with a herniated disk in his back, has struggled to regain his power. He is batting .252 with only five homers and 23 runs batted in, compared to last year when he batted .280 with 23 homers and 78 RBIs in 113 games.

Yet Wallach has been invaluable in his leadership role and has committed only one error all season.

“He’s a very important part of this team,” Claire said. “I don’t think there’s a person in that clubhouse or person in this organization who doesn’t believe that.

“I believe Tim will be back, but if not, we’ll see what our options are.”