Freddie Roach doesn't expect comeback from Jon Jones

While fight fans wait to hear the length of a pending suspension and possible return for Jon Jones, legendary boxing coach Freddie Roach isn't holding his breath.

The 28-year-old fighter is facing a potential two-year doping ban after previously being held out of action due to legal issues in 2015. Roach says he's been disappointed by Jones, who he gave an award for world's best MMA fighter in 2012, and thinks that layoff could be enough to end the fighter's career.

"Two years is going to kill him," Roach told Sherdog.com. "I feel like it will be the end of his career."

Jones has claimed that he took a tainted substance, an excuse that's been criticised by fellow fighters, as well as Roach.

"It's like I said to people, 'if someone gives you something, you better f---ing know what's in it because you can't trust anybody in this f---ing sport'," said Roach. "I mean, you can't. It's plain and simple."

Roach explains that fighters, their trainers and coaches have to be aware of people trying to take advantage of them. He says that this is a normal occurrence when training his fighters, including boxing great Manny Pacquiao.

"I've had that problem in the past before, where they wanted, like Manny, to drink something before a workout and I say 'what's in there?' and (the response is) 'don't worry it's just vitamins'. I say 'if he drinks that, will he pass a drug test?' and it's like 'don't know,'" said Roach. "What do you mean? I don't know? You've got to be careful, especially with people who aren't part of the camp."