BALTIMORE — The NFL postponed the Ravens’ Thanksgiving Day game against the Pittsburgh Steelers to Sunday afternoon amid a coronavirus outbreak, disrupting Baltimore fans’ plans to watch the game on the holiday.

Three more Ravens — defensive end Calais Campbell and offensive linemen Patrick Mekari and Matt Skura — were placed on the reserve/COVID-19 list Wednesday, after all reportedly tested positive. Five other players have been added to the list since Friday, a spike in cases that forced the NFL to move Thursday’s rematch in Pittsburgh to a 1:15 p.m. kickoff. The game will be broadcast nationally on NBC.

The Ravens’ outbreak has weakened an already vulnerable team headed to Pittsburgh (10-0) on a two-game losing streak.

Seven Ravens who were on the reserve/COVID-19 list, which is for players who have tested positive or are considered a “high-risk” close contact, are either starters or significant contributors. Under coronavirus protocols, any player who returned a positive test taken after Monday would likely miss both the Steelers game and the Ravens’ next game, a Dec. 3 matchup with the Dallas Cowboys.

In a statement Wednesday, the Ravens said an unnamed staff member had been disciplined for “conduct surrounding the recent COVID-19 cases that have affected players and staff.” According to the NFL Network, the staff member was a strength and conditioning coach who had failed to report symptoms and had not consistently worn a mask or tracking device, as required by NFL protocols.

The NFL’s decision to postpone Thursday’s game came less than 24 hours before the league’s Thanksgiving Day schedule was set to begin.

Dr. Allen Sills, the league’s chief medical officer, told the NFL Network Wednesday that, through contact tracing and other measures, NFL officials “feel like we have a really good handle on exactly when transmission occurred and how it occurred.”

“Obviously, you have to take each day as it comes and look for any new data that may emerge, but right now, we simply feel that, as of tomorrow, we would not have confidence in going forward,” Sills said. “But I think we feel we’re very close to the end of that transmission event.”

Wednesday’s postponement marked the NFL’s first schedule change since Week 7, when the league moved the Las Vegas Raiders-Tampa Bay Buccaneers game out of its important Sunday night time slot “out of an abundance of caution” due to COVID-19 concerns.

In early October, the Ravens (6-4) had their Week 7 game against the Steelers postponed.