Alistair Overeem apologizes

Top-rated heavyweight contender Alistair Overeem issued an apology Monday, three days after officially being removed from UFC 146 after testing positive for testosterone levels higher than those permitted by Nevada athletic regulators.

In the apology, Overeem said medication for a rib injury caused his testosterone level to increase. He said he is a clean fighter and took medication for the injury without knowing it contained testosterone.

Overeem was slated to face heavyweight champion Junior dos Santos on the May 26 card in Las Vegas, but was replaced by Frank Mir after failing a random drug test March 27 issued by the Nevada State Athletic Commission.

"I cannot express how sorry I am to the Commission, Junior dos Santos, the fans, the owners and employees of the UFC, my friends and family and anyone else who this has affected," Overeem said in a prepared statement.

The six heavyweights scheduled to appear on the UFC 146 card, including Overeem, were tested. All the test results came back negative except Overeem's, said Keith Kizer, the executive director of the Nevada commission.

Overeem's test results revealed a testosterone-to-epitestosterone ratio of 14-to-1. Under Nevada commission rules, a fighter's T/E ratio must not exceed 6-to-1.

The former Strikeforce champion said it was his decision to withdraw from UFC 146, which will be held at MGM Grand Garden Arena in Las Vegas.

"I am deeply saddened to announce that on Friday, April 20, I respectfully withdrew from the May 26 event so that I can request a continuance until my situation with the Nevada State Athletic Commission is resolved," Overeem said.

"I absolutely do not believe in, nor do I use performance-enhancing drugs. I am a clean fighter and I will do whatever it takes to prove this to everyone.

"Prior to the UFC 146 press conference in March, I aggravated an old rib injury on my left side. My doctor prescribed, and I accepted, an anti-inflammatory medication that was mixed with testosterone.

"I was completely unaware that testosterone was one of the ingredients in the medication. Although I was unaware, I do realize it is my job to know what I am putting into my body."

Overeem earned the title shot on Dec. 30 when he knocked out Brock Lesnar in the first round of their elimination bout.

Former UFC heavyweight champion Cain Velasquez, who was originally scheduled to face Mir, will take on Antonio Silva in the UFC 146 co-main event.