On the heels of her first loss, UFC strawweight Cynthia Calvillo has been dealt another blow.

Calvillo (6-1 MMA, 3-1 UFC) has been informed of a potential violation by the U.S. Anti-Doping Agency stemming from a positive drug test for marijuana, the UFC announced late Wednesday night.

The positive test stems from an in-competition sample collected in conjunction with UFC 219, which took place Dec. 30 at T-Mobile Arena in Las Vegas. Calvillo that night lost via unanimous decision to former champion Carla Esparza.

The 30-year-old Calvillo, who’s only fought professionally since 2016, was named MMAjunkie’s “Newcomer of the Year” for 2017. She fought her first four fights in the UFC last year, going 3-1.

Below is the full statement from the UFC:

The UFC organization was notified today that the U.S. Anti-Doping Agency (USADA) informed Cynthia Calvillo of a potential Anti-Doping Policy violation involving Carboxy-Tetrahydrocannabinol (“Carboxy-THC”) which is a metabolite of marijuana and/or hashish, above the decision limit of 180 ng/mL, stemming from an in-competition sample collected in conjunction with her recent bout in Las Vegas, Nevada on December 30, 2017, UFC 219: Cyborg vs. Holm.

USADA, the independent administrator of the UFC Anti-Doping Policy, will handle the results management and appropriate adjudication of this case involving Calvillo, as it relates to the UFC Anti-Doping Policy and future UFC participation. Because the Nevada Athletic Commission was the regulatory body overseeing the fight in Las Vegas and has licensing jurisdiction over Calvillo, USADA will work to ensure that the Nevada Athletic Commission has the necessary information to determine its proper judgment of Calvillo’s potential anti-doping violation. Additional information will be provided at the appropriate time as the process moves forward.

For more on UFC 219, visit the UFC events section of the site.