The Detroit Lions placed six players on the reserve/COVID-19 list this past week and had 12 others and six coaches who battled the flu, sources told ESPN on Saturday, leading to a potential roster crunch ahead of Sunday's game against the Denver Broncos.

One of the players on the COVID list is running back Jamaal Williams, who went through practice Friday before being informed afterward that he had tested positive, according to a source.

The Lions are concerned that anyone around Williams could either contract the virus or be deemed a close contact. Tests will continue Sunday morning in Denver as the team waits to see whether any more players need to be added to the reserve/COVID-19 list before kickoff.

The Lions were having discussions Saturday night to determine what measures they may need to take if additional players test positive for the virus ahead of the game, according to sources.

One scenario that has come up is delaying the game until Monday night, though there were no active discussions about that happening as of Saturday night, according to sources.

Williams has been ruled out for Sunday and could miss next week's game against the Arizona Cardinals as well.

The Lions already were facing availability questions at running back. D'Andre Swift, who has been battling a shoulder injury suffered on Thanksgiving, is a candidate to be placed on injured reserve, according to a league source.

For now and perhaps for the rest of this season, the Lions are expected to lean on a combination of running backs, including Godwin Igwebuike, Jermar Jefferson and Craig Reynolds.

Reynolds is one of seven players recently added from the practice squad, including six who have been designated as COVID-19 replacements on the roster. The others are defensive back Corey Ballentine, linebacker Curtis Bolton, defensive tackle Bruce Hector, defensive back Parnell Motley, defensive back Nickell Robey-Coleman and tight end Shane Zylstra.