He could very well be banned for years and fined his entire purse. Steroids are worse than weed but if a guy fails like 3+ times it is clear he has no respect for the commission and they have no choice but to throw the book at him. If they don't, other athletes are not going to give a shit either.
Fingers crossed, he gets banned for life. I can live without Diaz douchebaggery in MMA.