Tyrann Mathieu's start to the 2021 season has met an interruption.
Mathieu tested positive for COVID-19 and is going on the reserve/COVID-19 list, NFL Network's Tom Pelissero reported.
Depending on Mathieu's vaccination status, he could be back in a fairly short amount of time. Vaccinated players need two negative tests at least 24 hours apart to return to the team, while unvaccinated players are required to isolate for at least 10 days and test negative before being able to return to the team.
Mathieu hadn't been vaccinated when asked about it in April, but said he'd hoped to get vaccinated soon.
If Mathieu is vaccinated, he'll be able to return in a shorter window of time, provided he tests negative twice within the aforementioned 24-hour period. If not, his status for Kansas City's Week 1 game against the Cleveland Browns, which is just 11 days away, could be in jeopardy.