Analysis: Omicron looms ominously over NFL's playoff races

New York Giants' Mike Glennon passes during the second half of an NFL football game against the Philadelphia Eagles, Sunday, Dec. 26, 2021, in Philadelphia. (AP Photo/Matt Rourke)

Denver Broncos quarterback Drew Lock (3) walks off the field after the Broncos lost to the Las Vegas Raiders in an NFL football game, Sunday, Dec. 26, 2021, in Las Vegas. (AP Photo/David Becker)

Detroit Lions quarterback Tim Boyle walks off the field after an NFL football game against the Atlanta Falcons, Sunday, Dec. 26, 2021, in Atlanta. The Atlanta Falcons won 20-16. (AP Photo/Brynn Anderson)

Baltimore Ravens quarterback Josh Johnson throws before an NFL football game against the Cincinnati Bengals, Sunday, Dec. 26, 2021, in Cincinnati. (AP Photo/Jeff Dean)

Cincinnati Bengals quarterback Joe Burrow (9) leaves the field after an NFL football game against the Denver Broncos, Sunday, Dec. 19, 2021, in Denver. The Bengals won 15-10. (AP Photo/David Zalubowski)

New Orleans Saints quarterback Ian Book jogs off the field after an NFL football game against the Miami Dolphins Monday, Dec. 27, 2021, in New Orleans. The Dolphins won 20-3. (AP Photo/Derick Hingle)