Tyrann Mathieu has been placed on the NFL's reserve/COVID-19 list after he tested positive for the virus.

According to a source, the Kansas City Chiefs safety is vaccinated.

To be moved off the reserve/COVID-19 list and cleared to play, Mathieu will need to test negative twice within a 24-hour period and be asymptomatic.

The Chiefs open the regular season on Sept. 12 against the Cleveland Browns at Arrowhead Stadium.