SCOTTSDALE, Ariz. -- Reliever Jeremy Affeldt has that familiar goofy grin on his face this spring, and unlike most of 2013, he swears it's genuinely goofy.

"Even when I tried to be happy last year, it was fake," Affeldt said, reflecting on a season in which he deceived the training staff, incurred the scorn of the Giants' fan base for his ineffectiveness and finally -- literally -- collapsed in a heap trying throw a pitch with an injured groin muscle he says bothered him off and on for 11 years.

Affeldt's miserable season officially ended when he underwent what was termed sports hernia surgery Sept. 26. It was far more complicated than that. Scar tissue that had built up for years in his left groin finally gave way and fully detached from the pelvic bone. Tissue had to be repaired and reattached. Grisly stuff.

But after 10 weeks of physical therapy and a more stringent conditioning and maintenance program, the 34-year-old left-hander said he feels better than he has in years. There is no pain in the groin, just some weakness he maintains doesn't affect him when he pitches.

"It feels great," he said. "It'll be a full year before I feel at full strength, but as strong as I am right now, it showed me how weak I really was last year."

Failing to reveal to the training staff just how badly he was hurting, Affeldt tried to pitch without much function in his push-off leg, and the results were predictably ugly. His fastball lost its zip. He couldn't control his once devastating curveball.

"It was terrible," he said. "Every time I was out there pitching, I'd be thinking, 'Why am I in the big leagues right now? This is hideous. There are Little Leaguers who can throw a curveball better than I am right now.' "

Finally, as we was warming up in the bullpen for a game against Arizona on July 20, he fell trying to throw one pitch. Then, attempting a curveball, he airmailed one over the catcher's head and nearly hit the third base coach.

Worse yet, over the next two months, he probably shouldn't have tried to work his way back from the disabled list. He returned for one game against the Dodgers on Sept. 12 but faced only three batters, gave up two hits and finally surrendered to the injury. He flew to Philadelphia to see a specialist, who determined immediately that Affeldt needed surgery.

"I'd had problems with this groin since 2002," he said. "I didn't say anything then, either. I had to make the team, so I just wrapped it up and pitched with it. For years, I would basically mask it by wrapping it, and it was working. So that's why when it came up again last year I told them I thought it'd be all right, let's just wrap it and go. But it just got worse and worse.

"I coughed up 3-4 wins during that stretch where I was going really bad. I couldn't pitch, but I was still trying to go out there and do it. Should I have tried to be a hero? Not in that season. It wasn't a playoff run. But did it work out for the good? Yeah, because if it'd just gone away, it might have come back this year. But how I went about it was not the right way."

Affeldt said he tells trainer Dave Groeschner every day how he's feeling, even if it's just a minor ache. He had a minor hamstring issue early on, but lately, all he has been telling him is that he's fine. His results have been fine, too. In five outings, he has given up only one earned run.

"I can just pitch. I don't have 15 things to think about on my delivery trying to protect my leg," Affeldt said. "It makes for a lot of joy coming to the ballpark again."

  • It was a big day for two of the Giants' mainstays. Opening Day starter Madison Bumgarner threw five scoreless innings, allowed a mere two hits and walk with four strikeouts, and has yet to be scored upon in 14 spring innings.

    Hunter Pence, meanwhile, slammed two home runs, one to left-center and one to right-center, and also hit a vicious line drive that nearly took the head off the third baseman.

  • Health updates: Angel Pagan (back stiffness) could play in a game by Sunday, Bochy said. Second baseman Marco Scutaro undertook a third straight day of batting and infield practice and might play in a minor league game by Tuesday if there are no setbacks.

  • The Giants optioned infielder Nick Noonan and outfielder Roger Kieschnick to the minor league camp.