Minnesota Vikings running back Roc Thomas has been suspended by the NFL for three games for violating the league's substance abuse policy, ESPN's Adam Schefter reports.

The 23-year-old back is a returning player on the Vikings' practice squad. Thomas, at 5-foot-10, made his big league debut after signing as an undrafted free agent with Minnesota in Week 4 against the Los Angeles Rams. In November of 2018, the Vikings waived Thomas and re-signed him to the practice squad.

Thomas only appeared in five games for Minnesota in his rookie season, rushing for 30 yards in eight attempts. The Alabama-born athlete first attended Auburn University before transferring to Jacksonville State in the FCS.

Thomas was heading into training camp with the Vikings competing for a backup RB spot behind the team's 2017 second-round selection Dalvin Cook, who played at Florida State. The third-year back Cook has rushed for nearly 1,000 yards in his brief NFL tenure.

Thomas was also facing stiff competition from fellow backup suitors like Cincinnati product and undrafted free agent pick-up Mike Boone and veteran back Ameer Abdullah, looking for a second chance after minimal playing time with the Purple and Gold last year.

Roc was arrested in January of this year for felony-level possession of marijuana (five grams, per ESPN).

Despite the suspension, Thomas can practice with the team and participate in Minnesota's preseason matchups but will be barred from team activities from the start of the regular season until September 23.