Rich Harden’s latest injury will wipe out the Canadian’s 2012 season.

The oft-injured Oakland Athletics starter had surgery to replace a torn capsule in his shoulder, a problem the Victoria native has pitched through the past four years.

Harden originally suffered the injury on April 15, 2007, while attempting to field a comebacker with his bare hand while pitching for the A’s against the New York Yankees.

Harden went 1-2 with a 2.45 earned-run average in only 25 2/3 innings that season because of an inflamed right shoulder, and didn't pitch after July 7. He threw two simulated games late in the season with the hopes of making two final starts, but ultimately decided it wasn't worth risking further injury.

"To be honest," Harden said, "I'm relieved to have it over and move forward. It's been a long time since I felt the way I should."

Oakland, along with the Chicago Cubs and Texas Rangers — with whom Harden pitched from 2008 to 2010 — were aware of the injury but it wasn’t made public because of medical privacy laws.

"There’s no reason, if I work hard, I can’t get back to where I was before," Harden, who intends to pitch next season, told the San Francisco Chronicle on Wednesday.

Harden’s injury, which has put the career of New York Mets left-hander Johan Santana and forced Oakland’s Dallas Braden to have surgery last summer, caused a significant drop in his velocity and led to several other physical ailments as Harden compensated for pitching with an unstable shoulder.

Revamped mechanics

He was unwilling to reveal the severity of the injury to the point where Harden completely revamped his mechanics after the 2007 campaign with the help of A’s pitching coach Ron Romanick.

But the 30-year-old increasingly had difficulty finding consistency with his arm slot, his location and feel before opting for surgery last week, even though the free agent continued receive contract offers.

"Yes, I've been injured a lot, but nobody really knew what I'd been dealing with for five years," said Harden. "Every day, just to play catch, I had to re-train my body to throw. I'd start the game throwing 86-87 miles per hour and that was max effort."

Harden struggled in 15 starts last season, going 4-4 with a 5.12 ERA and 1.43 WHIP (walks plus hits per innings pitched).

When he returns to the mound, Harden said he would like it to be as a relief pitcher.

He missed the first three months of last season with an injury behind his pitching shoulder.

Harden received a one-year, $1.5 million US contract in December 2010 to rejoin Oakland, the team that drafted him in the 17th round in 2000.

He went 5-5 with a 5.58 ERA in 20 appearances and 18 starts for the Texas Rangers in 2010, when he struggled with injuries and control.

Harden spent two stints on the disabled list that season, first from June 12-July 30 with a strained left gluteal muscle and later with right shoulder tendinitis. Texas released him after the regular season.

In 2006, Harden was 4-0 in nine games, spending time on the DL with a strained back and then a strained elbow ligament.