Many changes and ideas have been proposed during the NFL owners' meetings, but one of them may not sit well with players, both current and retired.The NFL has, in recent weeks, been mulling expanding flex-scheduling to Thursday Night Football, which currently airs on Amazon's Prime streaming service. Flex-scheduling allows networks to move Sunday afternoon games to night spots, beginning in week 5. The idea is to put more relevant games between top teams on primetime.ABC/ESPN's Monday Night Football has already been added to 2023's flex-scheduling, but the addition of TNF was proposed at the owners' meeting on Tuesday (US time). Moreover, the NFL will now allow teams to play two Thursday games in a season, per Tom Pelissero of the NFL Network:Tom Pelissero@TomPelisseroThe Thursday Night Football flex scheduling proposal was tabled until May, per NFL EVP/Chief Media and Business Officer Brian Rolapp. However, owners did approve a change that will allow a team to play two TNF games in a season.722155The Thursday Night Football flex scheduling proposal was tabled until May, per NFL EVP/Chief Media and Business Officer Brian Rolapp. However, owners did approve a change that will allow a team to play two TNF games in a season.For clarity, though, the season opener and Thanksgiving, among other days, are off limits:Tom Pelissero@TomPelisseroFor clarity, the change would allow a team to play on TNF *on a short week* twice in a season. So doesn’t include the Week 1 opener, a TNF game after a Thanksgiving game, etc.15721For clarity, the change would allow a team to play on TNF *on a short week* twice in a season. So doesn’t include the Week 1 opener, a TNF game after a Thanksgiving game, etc.Many players, though, are unhappy with the proposal. Eagles cornerback Darius Slay, in particular, had a rather choice word about it:"Hell naw… we need to take that s*** away!"Darius Slay@bigplay24slayHell naw… we need to take that shit away! twitter.com/mysportsupdate…Ari Meirov@MySportsUpdateThe NFL announced that teams can now have two Thursday Night Football games per season. Limit was one. Now that’s changed.Flexing for TNF is not happening … for now.6025393The NFL announced that teams can now have two Thursday Night Football games per season. Limit was one. Now that’s changed.Flexing for TNF is not happening … for now.Hell naw… we need to take that shit away! twitter.com/mysportsupdate…Reigning champion and MVP quarterback Patrick Mahomes summed up his thoughts in one emoji:Patrick Mahomes II@PatrickMahomes🤦🏽‍♂️ twitter.com/mysportsupdate…Ari Meirov@MySportsUpdateThe NFL announced that teams can now have two Thursday Night Football games per season. Limit was one. Now that’s changed.Flexing for TNF is not happening … for now.217741462The NFL announced that teams can now have two Thursday Night Football games per season. Limit was one. Now that’s changed.Flexing for TNF is not happening … for now.🤦🏽‍♂️ twitter.com/mysportsupdate…Retired quarterback Robert Griffin III concurred with Mahomes:Robert Griffin III@RGIII@PatrickMahomes So much for player safety128533@PatrickMahomes So much for player safetyTwo-time Super Bowl-winning guard Damien Woody used the same emoji as part of his reaction:Damien Woody@damienwoodyPlayer safety huh 🤦🏾‍♂️ twitter.com/mysportsupdate…Ari Meirov@MySportsUpdateThe NFL announced that teams can now have two Thursday Night Football games per season. Limit was one. Now that’s changed.Flexing for TNF is not happening … for now.61336The NFL announced that teams can now have two Thursday Night Football games per season. Limit was one. Now that’s changed.Flexing for TNF is not happening … for now.Player safety huh 🤦🏾‍♂️ twitter.com/mysportsupdate…Recently retired defensive end J.J. Watt offered two reasons - player safety and fans - on why he dislikes the proposal:"Flexing games from Sunday to Thursday is a terrible idea for two main reasons:1) Player SafetyYou can’t make this decision and also preach that player safety is a priority.2) FansPeople spending hard earned money to see their team play. Who’s paying to change their plans?"JJ Watt@JJWattFlexing games from Sunday to Thursday is a terrible idea for two main reasons:1) Player SafetyYou can’t make this decision and also preach that player safety is a priority.2) FansPeople spending hard earned money to see their team play. Who’s paying to change their plans?9031880Flexing games from Sunday to Thursday is a terrible idea for two main reasons:1) Player SafetyYou can’t make this decision and also preach that player safety is a priority.2) FansPeople spending hard earned money to see their team play. Who’s paying to change their plans?Griffin seconded him:"The NFL is now allowing teams to have TWO Thursday Night Football games per year. A league that continuously says it is all about improving player safety continues to put the health of its players at risk. Playing 1 game with only 3 days rest isn’t smart. Playing 2 is RIDICULOUS"Robert Griffin III@RGIIIThe NFL is now allowing teams to have TWO Thursday Night Football games per year. A league that continuously says it is all about improving player safety continues to put the health of its players at risk. Playing 1 game with only 3 days rest isn’t smart. Playing 2 is RIDICULOUS8026817The NFL is now allowing teams to have TWO Thursday Night Football games per year. A league that continuously says it is all about improving player safety continues to put the health of its players at risk. Playing 1 game with only 3 days rest isn’t smart. Playing 2 is RIDICULOUSFinally, Seahawks wide receiver Tyler Lockett urged the NFL Players' Association to take action:"We gotta do something about this"Tyler Lockett@TDLockett12@NFLPA we gotta do something about this twitter.com/mysportsupdate…Ari Meirov@MySportsUpdateThe NFL announced that teams can now have two Thursday Night Football games per season. Limit was one. Now that’s changed.Flexing for TNF is not happening … for now.293The NFL announced that teams can now have two Thursday Night Football games per season. Limit was one. Now that’s changed.Flexing for TNF is not happening … for now.@NFLPA we gotta do something about this twitter.com/mysportsupdate…What other changes were proposed at NFL league meetings, and which of them were approved?Besides Thursday's flex-scheduling, another major change announced at the meetings was allowing all players (except linemen, both offensive and defensive) to wear number zero. Jaguars wide receiver Calvin Ridley was the first player to adopt the number, announcing it on Twitter:CALVIN RIDLEY@CalvinRidley1Excited to be the first @Jaguars player to wear zero - shout out to @JagsEquip! #ReadyToWork116291351Excited to be the first @Jaguars player to wear zero - shout out to @JagsEquip! #ReadyToWork https://t.co/MfympKGWSlOther rule changes, per ESPN, include:Teams may now reduce preseason rosters only once.Fourth-down attempts may now be reviewed (proposed by the Texans).Tripping is now a personal foul.Running backs must now wear Guardian Caps during the preseason (linemen, tight ends, and linebackers started wearing them last year).Proposals that were not approved or discussed include:Allowing teams to nominate a third quarterback on game days.Giving teams a chance to convert a fourth-and-20 from their own 20 line in lieu of an onside kick attempt.Allowing teams to challenge roughing-the-passer penalties.Spotting the ball at the 25-yard line if a kickoff is fairly caught, or when a touchback occurs on a punt (instead of the 20 in the latter situation).