Two Tennessee Titans players have tested positive for COVID-19, a source told ESPN's Dan Graziano on Wednesday.

After two consecutive days with negative tests, coach Mike Vrabel had been hopeful that the Titans could return to their facility on Wednesday. Under NFL rules, that can no longer happen.

This puts Sunday's game against the Buffalo Bills in jeopardy.

The two tests Wednesday bring the total of Titans players and other staff members who have returned positive coronavirus tests since Sept. 24 to 22.

The NFL announced last week that the game between the Titans and Pittsburgh Steelers in Week 4 was postponed until Oct. 25.

Eight players last week, one this week and 11 overall this season -- defensive lineman Jeffery Simmons, offensive tackle Isaiah Wilson, linebacker Kamalei Correa, cornerback Kristian Fulton, wide receiver Adam Humphries, defensive lineman DaQuan Jones, long-snapper Beau Brinkley, wide receiver Cameron Batson, tight end Tommy Hudson, fullback Khari Blasingame and cornerback Greg Mabin -- have been placed on the reserve/COVID-19 list.

NFL commissioner Roger Goodell warned the league's 32 teams Monday of penalties, including potential forfeits of games, for violations of COVID-19 protocols that force changes in the schedule.

Sources told ESPN's Adam Schefter this past weekend that the NFL and NFLPA are investigating whether the Titans violated the league's coronavirus-related protocols.

The league and union have asked the Titans to turn over multiple videotapes of team activities so they can get a better idea of the root of the outbreak, sources told ESPN.

The franchise has continued daily testing since the NFL told the Titans to close their facility on Sept. 29, and the league sent all 32 teams a memo Thursday with a list of new protocols for clubs to follow when dealing with an outbreak or having been exposed to an outbreak during the coronavirus pandemic.

ESPN's Dianna Russini and Turron Davenport contributed to this report.