Pittsburgh Steelers tight end Vance McDonald has tested positive for COVID-19, the first player from the NFL’s last unbeaten team to be diagnosed with the novel coronavirus since the start of the regular season.

Team spokesman Burt Lauten says the club was notified of the positive test on Monday morning, hours after the Steelers improved to 8-0 with a 24-19 win over the Dallas Cowboys. McDonald immediately self-quarantined and the Steelers remain in the NFL’s intensive protocol.

McDonald missed Friday’s practice with an “illness” according to the team’s injury report, but traveled to Dallas with the team and played 24 snaps.