PEORIA, Ariz. -- There is more than just a twinge of remorse in Chad Qualls' voice when he talks about his struggles in 2010, though it's not the 7.32 ERA he posted for two teams that has him feeling repentant.

Qualls' biggest regrets from his lost season between stints with the D-backs and Rays was more about not letting his post-operation left knee adequately heal and, consequently, not shutting himself down when his mechanics became a mess because of the knee.

"I should have gone on the disabled list and took some time off," Qualls said this week. "But I kept telling everyone I was fine, that I'll fix it. They kept listening to me. I needed someone to tell me to shut up and put me on the disabled list.

"Looking back on it now, I should have taken more time. But I didn't. I wanted to help my team win games."

Today, Qualls, 32, is a member of the Padres' vaunted bullpen, statistically the best in the game last season with a collective 2.78 ERA. Qualls is here on a one-year contract worth a guaranteed $2.55 million. The Padres hold a club option for 2012.

Qualls said he's here with something to prove.

"I just want to prove to myself that last year was a fluke," he said.

Qualls' troubles didn't actually begin in 2010 but in August of the previous season when he suffered an injury to the knee trying to field a ball hit hard up the middle. Qualls was told he needed surgery to repair both his medial and lateral meniscuses in the left knee.

But by the time he prepared for his September surgery, the diagnosis had gotten worse.

"It got written off as just a basic surgery," he said. "But I ended up tearing both of my meniscuses, part of my quad and I tore another ligament off my femur. It was supposed to be a four-month rehab."

The subsequent rehabilitation to the knee took longer than expected and essentially left him scrambling to get ready for Spring Training last season. But the knee wasn't ready. Qualls wasn't himself once camp began, having lost 25 pounds. And worse yet, the left leg and muscles were dramatically weakened.

The season began and Qualls, who saved 24 games in 2009, struggled from the outset.

"He's not an excuse-maker but his health at the beginning of last season was tough for him to overcome," said A.J. Hinch, the Padres' vice president of professional scouting who was Qualls' manager last season with the D-backs.

"As things got under way and the bullpen struggled, he bore the brunt of the blame. It continued to snowball on him to the point where he had the year that is very unlike the Chad Qualls we've known."

Qualls, who entered last season with a career ERA of 3.32 in his first six Major League seasons, found that his weakened knee led to mechanical issues for which he couldn't find a cure.

"I could still throw, but I wasn't throwing the ball the right way," he said. "I was using a lot of arm and no body. My sinker was flat, my slider was terrible. If you take those two pitches away from me ... then I basically don't have anything."

Qualls went 1-4 with four blown saves in 16 opportunities and had an 8.29 ERA with the D-backs. He was traded to the Rays on July 31, and Qualls didn't fare much better, posting a 5.57 ERA with three blown saves in his only three opportunities.

"I was trying to correct these things in the ninth inning, in tight ballgames," Qualls said. "Things started to compound. I just kept going out there and I kept digging myself in a deep hole."

Following an offseason strength-and-conditioning program in Austin, Texas, Qualls said that his knee has never felt better. He hired a trainer, and the pitching coach at the University of Texas, Skip Johnson, helped him with his mechanics.

Qualls is looking ahead now, to helping the Padres and, someday he hopes, being able to close games again at the Major League level.

"I would like to close again, but I'm happy to be on this team and pitch wherever [San Diego manager Bud Black] wants me to pitch," Qualls said. "I just want to be back to myself, be out there pitching well. I don't care if it's the sixth or seventh inning."