Dodgers’ Clayton Kershaw isn’t happy with his slider

Reporting from Phoenix -- Clayton Kershaw was dissatisfied with how he threw his slider Sunday in the Dodgers’ 7-1 defeat to the Milwaukee Brewers.

In fact, Kershaw hasn’t liked the way he has thrown the pitch this spring.

“It’s not where I’d like it to be,” Kershaw said.

The slider has been widely credited for transforming Kershaw from a high-ceiling prospect to a star. Looking for an off-speed pitch that could be called for a strike, Kershaw began throwing the slider with regularity in the second half of the 2010 season.

Kershaw pitched six innings in his penultimate start of the spring, giving up two runs, six hits and two walks. He struck out two. He is scheduled to make his final spring start March 31 and start on opening day in San Diego on April 5.

Kershaw has a 1.47 earned-run average this spring.

Complaints about his slider aside, he thinks he’s ready for the start of the season.

“Physically, this is the best I’ve felt,” he said. “I feel good. Arm feels good. I feel ready to go.”

Plate umpire Alfonso Marquez’s tight strike zone made it difficult to judge Kershaw on Sunday. Manager Don Mattingly visited Marquez in the middle of the fifth inning.

“I was playing peacemaker,” said Mattingly, noting that catcher A.J. Ellis and Marquez were becoming upset with each other. “We don’t need any of that right now.”

Regardless, pitching coach Rick Honeycutt agreed with Kershaw’s assertion about his slider.

“It has been inconsistent,” Honeycutt said.

On the plus side, Kershaw is encouraged by his changeup, a pitch he has seldom used.

Asked whether he would feel comfortable throwing the changeup more in the regular season, he replied, “It’ll be there when I need it. I feel a lot better with it than I did at the beginning of the spring and last season.”

Ted Lilly has a stiff neck

Ted Lilly’s stiff neck could force the Dodgers to realign their rotation at the start of the season.

Lilly passed up a scheduled bullpen session Saturday and was still inactive Sunday. Mattingly said he anticipated that Lilly would not make his scheduled start Tuesday.

That could force Lilly to be sidelined for the first series of the season. He was scheduled to start the third game.

But even if Lilly sits out the series, the Dodgers wouldn’t have to add any pitchers to their rotation because of the availability of fifth starter Chris Capuano. With a day off after the four-game series in San Diego and Kershaw scheduled to pitch the home opener April 10, the Dodgers have been planning to skip Capuano’s first turn in the rotation. Capuano would pitch in San Diego if Lilly can’t.

Short hops

Utilityman Adam Kennedy suffered a slight right groin pull when he slipped off second base on a defensive play. Trainer Sue Falsone said Kennedy is day to day. … Kenley Jansen, Mike MacDougal and Todd Coffey each pitched a scoreless inning in a minor league game. … Blake Hawksworth, whose recovery from an elbow operation has been stalled, could be put on the 60-day disabled list. That would open up a spot on the 40-man roster, which could go to a non-roster player competing for a place on the opening-day roster. Candidates include pitchers Jamey Wright and John Grabow, third baseman Josh Fields and utilityman Luis Cruz.

dylan.hernandez@latimes.com