Moises Alou joined a growing list of Mets starters that were sidelined with injuries for Johan Santana's first impressive outing in a New York uniform.

Alou became the sixth of eight regulars — and one pitcher — out with injuries when he returned to New York on Wednesday for tests on his right groin and learned he will need hernia surgery.

The oft-injured Alou will have the operation today and miss the start of the season. The 41-year-old left fielder is expected to resume baseball activities in four to six weeks.

"I myself have never seen so many injuries at one time," general manager Omar Minaya said. "The good thing is it's early in camp."

Besides Alou, the Mets are missing first baseman Carlos Delgado (right hip), right fielder Ryan Church (concussion) and catcher Brian Schneider (hamstring). Center fielder Carlos Beltran (knees), second baseman Luis Castillo (right knee) and pitcher Orlando Hernandez (toe) have yet to play in a spring training game because they're still rehabbing from offseason surgery.

The news on Alou overshadowed Santana's second spring start. The two-time Cy Young Award winner showed off his changeup, striking out four in three innings in New York's 3-2 victory over the Los Angeles Dodgers.

"I'm fine. I'm right where I'm supposed to be," said Santana, who threw 54 pitches.

The Dodgers aren't free from injury, either.

Second baseman Jeff Kent was scratched from the lineup because of a strained hamstring. He could miss at least a week.