VERO BEACH, Fla. -- Los Angeles Dodgers third baseman Andy LaRoche had no idea getting hit by a baseball could do so much damage.

LaRoche tore a ligament in his right thumb trying to catch a pickoff play at third base during Friday's 6-4 loss to St. Louis. He will have surgery Monday in Los Angeles and miss eight to 10 weeks, taking him out of a two-man competition at third and making Nomar Garciaparra the probable opening-day starter despite his own injury.

"I guess you can't say it's as bad as finding out someone died or something, but it's a shock," LaRoche said Saturday. "You don't believe it at first. I just got hit by a baseball, but it's just one of those things you've got to accept it."

LaRoche entered the game in the fourth inning as a pinch runner for Garciaparra, who was hit by a pitch on his right wrist.

A half inning later, the 24-year-old LaRoche was injured when catcher Danny Ardoin's pickoff throw to third deflected off runner D'Angelo Jimenez and jarred his thumb.

LaRoche batted .350 in nine spring games with a home run and two RBIs.

Garciaparra suffered swelling and bruising from the hit and is day to day but X-rays found no serious problems.

"The thing with the hand is there are so many little bones in there you just don't know, so we just wanted to go make sure. Obviously, it was good to hear nothing was broken," said Garciaparra, who is batting .375 after hitting just .283 last season.

Garciaparra was scheduled to leave Wednesday for Beijing, where the team will play two exhibition games against the San Diego Padres.

LaRoche expected to return to Vero Beach by Wednesday or Thursday after his surgery so he can continue working out.

Though his thumb will be immobile at first, trainer Stan Conte told him his rehabilitation will begin with exercises such as playing video games, which is "not a bad way to rehab," LaRoche said.

After three to six weeks, he should be able to start hitting and throwing again.

"You just try to keep your spirits up and try not to miss a beat conditioning wise," LaRoche said. "You just hope and pray for a strong recovery."