James Irvin has had to overcome more than just a spate of knee injuries in his two-year journey back to UFC competition.

Irvin earned the admiration of fans in his early UFC career for his violent knockout power. He needed just eight-seconds to KO Houston Alexander in one fight, and knocked out Terry Martin in another with a spectacular flying knee just nine-seconds into the second round of their battle. His nickname "The Sandman" seemed well-earned, as he appeared capable of knocking out anyone he faced with a single flush shot.

But beneath his confident demeanor and chiseled physique, Irvin was fighting a battle against a different kind of foe.

His problems began with a fight against Thiago Silva at UFC 71, a fight he lost after badly tearing the ligaments in his right knee. Irvin experienced prescription painkillers for the first time in the aftermath of that fight, and though he was able to stay off of them for a time, the injuries - and the meds - kept coming.

"It wasn't until a time that I just stopped taking them that I realized I needed them just to keep on functioning," Irvin told The Canadian Press. "At that time I had become an addict and I was hooked on them. I never even heard the word withdrawal. I didn't know what withdrawals were. I didn't know what was going on. I didn't know to speak to a doctor about it. I took it the wrong way, kind of the cowardly path. I just kept on using the prescription drugs, but it's a tough push-pull kind of thing in my line of sport. Injuries are a common thing, it's something you're always dealing with. And when you have bad ones, sometimes you have to take those medications."

For Irvin the end of the line would come with his knockout loss to Anderson Silva at Ultimate Fight Night 14. In the aftermath of the fight, Irvin tested positive for banned painkillers and faced a fine and nine month suspension. He now considers getting caught a blessing.

"I needed to get caught," Irvin said. "I needed to get in trouble for it and wake me up and get off of those things. Since then, since I've had that suspension, (since) I've been drug-free, it's been the happiest time of my entire life. I can honestly say that," he added. "A lot of people throw that around, but I can tell you (it's true) with my family, with my wife, my training. I've found a new love in training again, it's something that I had lost while using those prescription drugs and I just feel like a new person."

Irvin has since returned to training with a passion, working as a trainer at the Ultimate Training Center which he co-owns in Sacramento. He's also worked hard to get back into the tremendous physical shape he enjoyed before his knee injuries, and his recovery has been so successful he's been able to run two marathons.

"The Sandman" believes it's important to tell his story to others, and at least once a month he takes time to visit a school or other forum to share his experience with drug addiction.

"It's been tough," Irvin stated. "My father was an alcoholic who took his life, my mother was a speed freak for three-quarters of her life. And I had never touched a drug, any drugs until I made it to the UFC when I had my first injury. So then...