The recent ban on testosterone replacement therapy (TRT) by the Nevada State Athletic Commission and later the UFC could force one of the most popular fighters in mixed martial art into retirement.
Chael Sonnen (28-4-1), a known user of TRT who has made a name for himself as a dominant wrestler and an animated presence behind a microphone, spoke Wednesday on "UFC Tonight" about the rule change and the effect it could have on his career.
"If this retires guys, then it retires guys. The rules are the rules, and the rules need to be followed," he said.
"I'm going through this myself, where I've had to stop testosterone with the hope that we can find a new way to gain the results of upping testosterone to stay at a healthy level. If it doesn't work, I may have to stop the sport. And it's as simple as that."
The TRT ban has already affected one of the sport's biggest names. Last week, middleweight title contender Vitor Belfort (24-10) was forced to pull out of his championship bout against Chris Weidman.
Lyoto Machida (21-4) has stepped in to take on the 185-pound champion at UFC 173 on May 24.
Belfort, who has never hid behind the use of TRT, sang a different tune about the potential impact the ban would have on his fighting future.
"As other jurisdictions may follow suit, I am going to drop my TRT program and compete in MMA without it," Belfort said in a statement provided to Fox last week.
Being that fighters, including Sonnen, feel that TRT is necessary for them to compete at the same level as their opponents, some red flags went up when Belfort didn't put up much of a fight against the ban.
"As it relates to Vitor, I think this was a very genuine and sincere thing for him," Sonnen said. "Here's the problem that I have: a fighter that said seven days ago, 'I need TRT or I can't do this,' and then all of a sudden goes, 'Well, I'll just stop TRT.' I find that very disingenuous."
Sonnen is scheduled to fight Wanderlei Silva in a grudge match between coaches in "The Ultimate Fighter Brazil 3" finale on May 31.