Thumb injury sidelines Dodgers’ LaRoche

VERO BEACH, Fla. – Andy LaRoche has a torn ulnar collateral ligament in his right thumb and will return to Los Angeles to undergo surgery in the next couple of days, General Manager Ned Colletti said today. LaRoche is expected to be sidelined for eight to 10 weeks, meaning he’ll be back in early May at the soonest.

LaRoche, 24, was competing with Nomar Garciaparra to be the Dodgers’ starting third baseman.

LaRoche was hurt in the fifth inning of the Dodgers’ 6-4 loss to the St. Louis Cardinals today, when a throw from Dodgers catcher Danny Ardoin to pick off a baserunner hit him between the thumb and index finger of his throwing hand and left the area swollen.

LaRoche entered the game as a replacement for Garciaparra, who was hit by a pitch above his right wrist a half inning earlier.

LaRoche and Garciaparra left the clubhouse together to undergo X-ray exams.

“We’re fortunate that Nomar didn’t have something more serious happen to him,” Colletti said.

Garciaparra hit one of the Dodgers’ three home runs against the Cardinals, the others coming from Andruw Jones and Andre Ethier. The homer was the first in a Dodgers uniform for Jones, who signed a two-year, $36-million contract this winter.

But Jones, a notorious free swinger, said he was more pleased about the discipline he had shown at the plate this spring than the home run.

dylan.hernandez@latimes.com