Here is why Steelers players are angry about Ravens game being postponed

Several Pittsburgh Steelers players have made it known that they are unhappy about their game against the Baltimore Ravens being postponed, and much of that has to do with what they perceive as inconsistencies in the way the NFL is handling COVID-19 cases.
Andrew Fillipponi of 93.7 The Fan in Pittsburgh said Tuesday that multiple Steelers players are “ticked off” that their game against the Ravens has been pushed back to Wednesday while the Denver Broncos were forced to play on Sunday with all four of their quarterbacks out. The Ravens-Steelers game was pushed to Wednesday from Tuesday due to “competitive issues,” in part because Baltimore has not been able to practice in over a week.
Because the game was moved to Wednesday, Ravens running backs Mark Ingram and JK Dobbins had enough time to be cleared from COVID-19. Many, including some Steelers players, feel that the NFL helped the Ravens by giving them more time but basically told the Broncos “too bad.”
That’s not what happened. ESPN’s Adam Schefter explained on Monday that the NFL decided to proceed with Sunday’s game between the Broncos and New Orleans Saints because they felt Denver’s COVID situation was contained, whereas the Ravens’ was not. Only Broncos quarterback Jeff Driskel tested positive, and the league ruled Denver’s three other QBs as ineligible to play due to being deemed high-risk contacts. There were no other positive tests and no other players who were deemed high risk.
You can read more of Schefter’s explanation here.
Simply put, the NFL is not playing favorites. The league has a protocol in place for determining when they believe the virus is contained. They were confident the exposure was limited to the Broncos’ four quarterbacks, so that game was played Sunday. The same could not be said for the situation in Baltimore.