In an effort to avoid further suspensions like the ones handed down to Tampa Bay Buccaneers wide receiver Antonio Brown and defensive back Mike Edwards, NFL officials spent the past week calling multiple teams to inquire whether players who had gotten COVID-19 had been vaccinated on site at the team's training facility or off site at another location, league sources told ESPN on Saturday.

League officials want further information on this to ascertain whether any other players have misrepresented their vaccination status, sources said. Teams have been leery about players using fake vaccination cards and have warned some of them about the severity of such an offense.

While there do not appear to be any active investigations over fake vaccination cards, the league wants to make sure no other players attempt to game the system.

Even Buccaneers coach Bruce Arians called for the league to take further and stronger action.

"There's a lot more to the story," Arians told reporters Friday. "I just hope they don't stop looking."

The league was so bothered by the actions of Brown and Edwards that it wanted to suspend them up to eight games, sources said. The league argued for six- to eight-game suspensions for each player, which would have ended their 2021 seasons.

But after negotiations and discussions with the NFL Players Association, the two sides settled on three-game suspensions for each of the three players disciplined this past week. Brown, Edwards and John Franklin III each were suspended three games, with each player waiving his right to appeal.

But others around the league are predicting that they will not be the last players suspended for their vaccination status.

Fake vaccination cards are not part of the jointly agreed to COVID-19 protocols, because such violations are federal offenses, and any player who attempted to use a fake vaccination card would open himself up to a federal investigation -- worse than discipline that the NFL could impose.