Minnesota Vikings send quarterback Kirk Cousins home from training camp due to undisclosed illness 4:00 PM ET Kevin SeifertESPN Staff Writer Close ESPN.com national NFL writer ESPN.com NFC North reporter, 2008-2013 Covered Vikings for Minneapolis Star Tribune, 1999-2008 EAGAN, Minn. -- The Minnesota Vikings sent quarterback Kirk Cousins home from training camp Thursday because of an undisclosed illness, according to coach Kevin O'Connell . Speaking after the team's early-afternoon walk-through, O'Connell said the team was not yet ready to say whether Cousins has COVID-19. The team will have a full practice later Thursday afternoon. "We're still in that process of trying to go through all that," O'Connell said, "and make sure first and foremost: 'What are you feeling? What's going on?' And then going through our in-house process to make sure that if that does end being [COVID], we're on top of it. If not, there's still some other stuff going around that we want to make sure that we're being smart about for the other 90 players and the coaches." Cousins missed one game last season after testing positive for COVID-19. He also quarantined for five days of training camp last summer because he was an unvaccinated close contact of backup quarterback Kellen Mond , who had tested positive. The NFL paused its remaining COVID-19 protocols in March. But all league employees -- including players -- are required to follow CDC guidelines that currently call for five days in isolation following a confirmed positive test. The illness makes it unlikely that Cousins will participate in Sunday's preseason opener against the Las Vegas Raiders , although it was possible he would not have played even if he were healthy. Mond and veteran Sean Mannion have been competing to be the team's No. 2 quarterback in camp.