Bobby Southworth returns to action this Friday at Strikeforce: Destruction. The former Ultimate Fighter Season 1 contestant faces one of the toughest challenges of his career when he takes Renato "Babalu" Sobral. The fight will be a five-round contest for Southworth's Strikeforce light heavyweight title.

The two fighters were originally scheduled to fight back in September, but Southworth was forced to withdrawal due to a knee injury.

"I had surgery on my knee one time to repair my meniscus. When they did the surgery, the doctor noticed my ACL was thinning. If I tweak my knee a certain way, my ACL kind of pings a little bit off kind of like a frayed piano wire. So my ACL has gone from 90 to 65 to 40 percent; I don't know what it's from," Southworth explained to "I have to go back and rehab my leg and make it stronger and do all these things to compensate for that.

"That's what happened and I'm really pleased with my recovery; my physical therapist and new trainer really went out of their way to give me the right kind of exercises to get my stability back; my strength and my explosion. I'm really liking it right now."

Southworth realizes he needs to be in the best physical shape when facing a dangerous opponent such as Babalu.

"You know you always want to be 100 percent going into a fight and it's really difficult. When I injured it, we went right away to therapy and tried to rehab it and get it better. I missed two and a half weeks of training a month out from the fight, so there really was no other choice," said the American Kickboxing Academy fighter. "You really don't want to go in and hobble into the cage against a fighter of Babalu's caliber so we thought it was best to pull out."

After Southworth announced his injury and subsequent withdrawal back in September, Anthony Ruiz was tabbed as his replacement to face Sobral. Ironically, Sobral's fight with Ruiz was scrapped when the Brazilian suffered a knee injury of his own during training. Now fully healed, both fighters are ready to go.

"That was a fight that Strikeforce was trying to put together for a while," Southworth said. "My knee injury and his knee injury unfortunately had held it off. I'm definitely excited to get in there with a fighter of Babalu's caliber. He's an icon and a legend in the sport. It's an honor just to be considered to compete against a fighter of that stature. I'm looking forward to it."

In a recent interview with Strikeforce's official website, Renato Sobral stated, "Bobby called me out and I gladly accepted the challenge. On Friday, the world will learn what Bobby already knows; that this was the biggest mistake of his career."

"That's fine if he thinks it's a mistake. To me, this is just a fight and I don't go and bring personal feelings into the ring; I think that's a mental distraction," commented Southworth. "It's going to be a tough fight. I don't know if it's a mistake to fight Babalu; it's a huge challenge for me and I've prepared for it. I'm ready to step up."

In preparation for this fight, Southworth has been training primarily with his team at American Kickboxing Academy.

"We have a lot of great fighters at our gym. The team is in full effect when everyone is there. There's so many bodies and everybody brings a unique set of skills into the ring and onto the mat. I couldn't ask for anything more."

Southworth has been fighting in MMA since 1999. At 38 years old, the Strikeforce champion may be nearing the end of his career.

"I'd like to stay as busy as I can, as busy as my body allows. I always hope to get in anywhere from three to five fights in any given year. I'm not a huge name in the MMA scene, but I'm not a nobody. I'm not going to take fights where I'm not going to be adequately compensated. Sometimes that plays into the decisions and the extended layoff that I've had in my career.

"It's unfortunate, but that's the way the fight game works. Some fighters are willing to sell themselves short in order to compete and I'm not going to do that. Some people think that my fighting style is boring, but the priority for me is to win the fight. As long as I'm winning, then I'm going to stay active in the game. As soon as I'm losing, it's just going to give promoters an excuse to phase me out and I'm not ready to be phased out. I take it fight to fight and we'll have to see what happens after this one."

On Friday, Southworth will have the opportunity to prove he has what it takes to overcome one of the biggest challenges of his career. A win would garner him the most significant victory of his career. A loss could leave him at a crossroads.

"I have been around for a while and I haven't had as many opportunities to face top competition as I would have liked. I've been waiting for an opportunity like this for a long time and I've prepared diligently for it. My camp has me ready and I'm excited."

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