BERKELEY, Calif. - It's a good thing Cal women's volleyball coach Rich Feller has a sense of humor. That's about the only way to cope with the rash of injuries the Bears have endured this season.

Just when it looked like the Bears may finally be getting a little healthier with the return of senior opposite Correy Johnson to full-time status, Cal lost starting outside hitter Adrienne Gehan to a knee injury Wednesday night during a 25-20, 25-18, 17-25, 25-15 Pac-12 Conference loss to No. 2 Oregon at Haas Pavilion.

Gehan went down during the first set and was replaced by freshman Lara Vukasovic, Johnson's backup who hasn't practiced at outside hitter all season.

"I've never had a season like this," said Feller, now in his 14th year at Cal and 28th overall as a head coach. "It's just the way it is sometimes."

Gehan is the Bears leading attacker at 3.36 kills per set. It wasn't immediately known how long she would be out of the lineup.

Cal has already suffered season-ending injuries to starting outside hitter Michelle Neumayr and starting libero Robin Rostratter. Backup middle hitter Lillian Schonewise has also has yet to play this season because of a shoulder injury.

"Lara has never gone in at left side, and she rarely plays back row at practice," Feller said. "She's the only one left to do it. She has some skills, but hitting the ball from that side is pretty different for her."

Considering the circumstances, the Bears played well. It was the first set Oregon (14-0, 5-0) has dropped in conference play this season and just the fifth overall. Ducks All-American outside hitter Alaina Bergsma, who entered the night ranked fifth in the Pac-12 with a .376 hitting percentage, hit at just a .234 clip. Oregon also began the day ranked sixth nationally with a .309 hitting percentage but converted at just a .205 mark against the Bears (8-7, 2-3).

"I love the heart. I love the way we competed," Feller said. "I wish we could have sustained it a little bit longer. But we were able to frustrate them a little bit, and some of their hitters weren't as effective as they have been all year."

One of the reasons the Bears slowed Oregon's offense was because they recorded a season-high 20 blocks. Senior middle hitter Kat Brown led Cal with 10, and in the process moved into a tie for third place on the school's all-time list with 434 for her career.

Senior middle hitter Shannon Hawari added nine blocks, Johnson had six and Christina Higgins had five.

"Twenty blocks is pretty unbelievable against an offense like that," Feller said.

The Bears trailed throughout the first set but were as close as 21-19 after Johnson and Brown blocked Bergsma. But the Ducks reeled off four of the next five points to take the lead.

Cal scored three points in a row in the second set, two courtesy of blocks by Hawari, to cut Oregon's advantage to 14-13. But the Ducks scored four in a row of their own and kept their distance the rest of the set.

The Bears raced out to a 7-2 lead in the third set, as Cal kept up its effective blocking. Oregon had a four-point run to get as close as 10-9, but the Ducks could never take the advantage. Cal easily cruised to the third set win.

But the Bears couldn't maintain the momentum into the fourth set. Oregon jumped out early and held a comfortable lead the entire way.

Cal returns to the floor Friday at 7 p.m. against Oregon State at Haas Pavilion. .