The Dodgers won another game, but lost another player.

On the same day they defeated the defending World Series champion St. Louis Cardinals, 6-0, second baseman Mark Ellis underwent an emergency leg operation that is expected to sideline him for a minimum of six weeks.

Ellis, who was injured when Tyler Greene of the Cardinals slid into him at second base the previous night, had blood and fluids drained from his left leg. He is scheduled to be hospitalized until Tuesday.

He became the fourth Dodgers starter on the disabled list. The others: Matt Kemp, Juan Rivera and Juan Uribe.

With half of their everyday position players sidelined Saturday, starting pitcher Clayton Kershaw responded the way he often responds in times of crisis.

Kershaw pitched a complete game, limiting the Cardinals to six hits. Only two visiting players reached scoring position, neither with fewer than two outs.

“As a team we’re going to have to step up,” Kershaw said.

Kershaw struck out four and improved to 4-1. He didn’t walk a batter.

The shutout was Kershaw’s first of the season and fourth of his career.

“He’s a handful, I don’t care who he’s facing,” Dodgers Manager Don Mattingly said.

The Dodgers improved to a major league-best 27-13, including 18-4 at Dodger Stadium.

The Dodgers went ahead, 2-0, in the fourth inning when a fielding error by substitute first baseman Matt Carpenter allowed Bobby Abreu and Andre Ethier to score.

Kershaw preserved the advantage, setting the stage for a four-run seventh inning that increased the margin to 6-0 and put the contest out of the Cardinals’ reach.

The four-run push started with a solo home run by Justin Sellers, who started at shortstop in place of the slumping Dee Gordon. Kershaw doubled and scored on a single by Tony Gwynn Jr., who later scored on a wild pitch. Ethier singled to center field to drive in his National League-leading 36th run.

“We’re getting hits from different people,” Mattingly said. “We just keep scratching.”

The win assured the Dodgers of a series victory against the Cardinals, who have lost seven of their last nine games but still lead the National League Central. The three-game series concludes Sunday.

The Cardinals have their own health problems. First baseman Lance Berkman exited the game after he stretched to catch a ball thrown his way by shortstop Rafael Furcal in the second inning and injured his right knee.

The visitors recently put two of their outfielders, Jon Jay and Allen Craig, on the disabled list.

Ellis’ injury threatened to affect his life after baseball.

Trainer Sue Falsone said that if pressure hadn’t been released from the lower half of Ellis’ left leg, his muscles could have been permanently damaged.

The incision on Ellis’ leg, which is several inches long, will not be closed until Tuesday because doctors want to continue to drain it of blood and fluids.

The source of the problem was a slide by Greene, who upended Ellis to break up a double play in the seventh inning of the Dodgers’ 6-5 victory Friday. Ellis reported to the clubhouse Saturday, complaining that his leg still bothered him.

Greene thought his slide was clean.

“I didn’t think he anticipated me being as close to the bag as I was,” Greene said.

Mattingly didn’t have any problems with how Greene slid into Ellis.

“We felt like it was clean,” Mattingly said. “We felt like it was a good, hard slide.”

Signed to a two-year, $8.75-million contract in the off-season, Ellis has displayed surprising range in the middle of the infield considering he is 34 years old. He was hitting .273 with two home runs and 19 runs batted in

“I think he’s a great player,” Mattingly said of Ellis. “He’s one of those guys, the more you see him, the better he is. It’s a tough guy to replace.”

Ellis will be replaced by infielderIvan De Jesus Jr., who was recalled from triple-A Albuquerque.

De Jesus is one of several utilitymen who could receive a share of the playing time at second base. Jerry Hairston Jr., who is expected to be activated Wednesday from the disabled list, figures to be part of the mix. So do Adam Kennedy, Elian Herrera and Sellers.

The starter Saturday was Herrera, a 27-year-old career minor leaguer who was called up from triple A earlier in the week.

dylan.hernandez@latimes.com