Linebacker Jeff Ulbrich, the San Francisco 49ers' second-leading tackler last season, will be placed on injured reserve after undergoing surgery today to reattach his biceps muscle to his arm.

The former University of Hawai'i standout, who is second in the NFC this season with 41 tackles according to league stats, spoke with several medical specialists before reluctantly deciding on surgery yesterday to repair a tendon on his right arm.

If he had attempted to play through the injury, which occurred while trying to tackle Indianapolis' Edgerrin James last weekend, he would have lost half of the strength in his arm for the rest of his life.

Though coaches, teammates and his wife urged the hard-nosed linebacker to have surgery, Ulbrich waited four days before deciding it was the only rational move. He will need at least four months to recover.

"I was trying to find a doctor that would say we can go in there 10 weeks from now and fix it, and it will be good as new," Ulbrich said. "I was searching for someone, but it's not out there."

VIKINGS

SEX PARTY ACCUSATIONS

Crew members on two chartered boats told authorities yesterday they saw Minnesota Vikings players take part in a wild sex party on Lake Minnetonka.

The workers told Hennepin County sheriff's deputies they had to step over and around players and naked women engaged in sex acts on the floor, said their attorney, Stephen Doyle of Wayzata.

Vikings running back Mewelde Moore said he attended the cruise, but didn't see any sex acts or other improper behavior.

"Nothing happened," Moore said. "They got it all wrong."