Kershaw, who signed a two-year, $19 million contract earlier this month, referred questions to the club's athletic training department. A team spokesman said Kershaw felt a tight muscle in the middle of his back during workouts before reporting earlier this week.
Wednesday was the first workout at Camelback Ranch-Glendale for pitchers and catchers, and Kershaw was originally in the first day's group to throw bullpen sessions. He did play catch and worked out at the various stations. He is not expected to throw a bullpen session before Friday.
While winning the pitcher's Triple Crown last year (wins, ERA and strikeouts), Kershaw also finished third in the league with a career-high 233 1/3 innings pitched. He turns 24 next month. During his first two seasons in the Major Leagues, manager Joe Torre tried to limit his pitches to 100 per start to protect his arm.
Speaking about Kershaw before Wednesday's workout, manager Don Mattingly had this to say about his ace's Spring Training routine:
"He's been around for a while, we know he's young and he's thrown a lot of innings and we won't do anything to jeopardize him."
The only injury Kershaw has suffered with the Dodgers was a separated right (non-throwing) shoulder in 2009 when he ran into an outfield fence while shagging fly balls.
Fellow left-handed starting pitcher Ted Lilly, still home after the Tuesday birth of his daughter, is expected in camp Friday.
Reliever Ronald Belisario, who had a tooth extracted Tuesday, also skipped his first bullpen session Wednesday but said he would make it Thursday. Non-roster pitcher Shane Lindsay was out with a slight latissimus dorsi strain.