The Baltimore Ravens learned that at least three members of the organization tested positive for COVID-19 on Wednesday, a source told ESPN, marking the fourth day of a coronavirus outbreak among the team that led to the postponement of Thursday's game against the Pittsburgh Steelers.

The new positive tests came from one player, one position coach and one staff member, the source said.

As of Wednesday afternoon, the Ravens had seven players who tested positive for COVID-19 or were identified as close contacts. Members of the Ravens' coaching staff and support staff have also tested positive.

The team issued a statement Wednesday saying an unnamed staff member has been disciplined "for conduct surrounding the recent COVID-19 cases that have affected players and staff at the Ravens."

The Ravens will now play at the Steelers on Sunday (1:15 p.m. ET, NBC), as the NFL decided to postpone the game to conduct more testing and contact tracing, a source told ESPN's Dan Graziano on Wednesday.

Baltimore closed its facility Monday morning before reopening in the afternoon, when the team held a walk-through. A day later, the Ravens shut down the facility again after more positive tests and conducted all team activities virtually, which they are continuing to do Thursday.

The Ravens' outbreak began hours after Sunday's 30-24 overtime loss to the Tennessee Titans, when the team learned running backs J.K. Dobbins and Mark Ingram had tested positive. Nose tackle Brandon Williams was later identified as a high-risk close contact.