Baltimore Ravens star player Lamar Jackson has tested positive for the coronavirus, US media reported Thursday.

The 23-year-old quarterback’s positive test leaves the status of Baltimore’s Sunday game against unbeaten Pittsburgh in jeopardy, because this is the fourth consecutive day a Ravens’ player has been diagnosed with Covid-19.

The Ravens’ COVID-19 outbreak resulted in the league rescheduling the Ravens-Steelers game from Thursday to Sunday, but the latest news complicates the situation further.

The Ravens have yet to release any details about the latest test results for Jackson, who is the NFL’s reigning most valuable player.

The team officially has 10 players on the Covid-19 list, which indicates a player has tested positive or is considered a high-risk close contact with an infected person.

Coach John Harbaugh told players that they would not be allowed back to the team facility until Monday at the earliest in the interest of safety, said US sports broadcaster ESPN.

If Jackson can’t play, the Ravens likely would turn to backup quarterback Robert Griffin, who has thrown just two passes this season, with one of those being an interception. Their other backup quarterback, Trace McSorley, is also on the Covid-19 list.