UFC star Anderson Silva reportedly tested positive for both a steroid and a diuretic in October.
Since methyltestosterone is an anabolic agent, it could yield a two-year suspension.
Silva tested positive for anabolic steroids following a UFC 183 tilt with Nick Diaz in 2015, which resulted in a one-year suspension.
The 42-year-old veteran was supposed to headline UFC Fight Night with Kelvin Gastelum in November 2017, but Silva was pulled from the fight due to his most recent positive test.
According to Raimondi, Silva could be suspended for as many as four years if the U.S. Anti-Doping Agency considers his previous positive test.
The Brazilian star hasn't fought since beating Derek Brunson at UFC 208 in February 2017. That win broke a string of five consecutive outings without a victory.
Silva is considered one of the greatest fighters in UFC history, as his 2,457-day run with the UFC Middleweight Championship still stands as the longest title reign in the history of the promotion.
Since Silva was already slipping in recent years, a suspension of any length could potentially spell the end of his illustrious career in the Octagon.