The NFL is reviewing footage of New England Patriots coach Bill Belichick grabbing a referee at the end of Sunday's 31-30 defeat at the Baltimore Ravens as criticism intensifies over replacement officials.
The stand-in referees, drawn from the lowly ranks of college and semi-professional football, are filling in for the regular officials who have been locked out this season due to a dispute with the league over a new collective bargaining deal.
Last week the league warned coaching and playing staff to treat the replacement officials with respect but there was little sign of that in Baltimore in Week Three's big game.
After the Ravens won with a field goal that flew over the top of the post, Belichick raced on and grabbed the arm of a referee and seemed to be questioning whether the score was legitimate.
Making physical contact with an official is likely to land the triple Super Bowl-winning coach with a hefty fine and Greg Aiello, the NFL's senior vice president of communications, told Reuters on Monday that the incident was being looked at.
"I'm not going to comment about that (incident)," said the 60-year-old Belichick in the post-game news conference. "You saw the game. What did we have, about 30 penalties called?".
The officials imposed 10 penalties for 83 yards on the Patriots and 14 penalties for 135 yards on the Ravens.
Ravens coach John Harbaugh was also handed a 15-yard penalty for unsportsmanlike conduct after appearing to bump into an official while yelling for a timeout.
"I didn't mean to bump him. I wanted to call a timeout so I apologize for bumping but the intention was to call a timeout," he said.
Across the league a weekend of thrilling action and upset results was accompanied by more and more concerns over the officiating.
Games were slowed down by excessive flags on plays, frequent reviews, confusion over challenges and numerous and debatable penalties.
Mike Pereira, former vice-president of officiating for the NFL and now a television analyst, said the replacement referees looked lost.
"It simply comes down to this - the replacement officials don't know the NFL rules, they don't know how to enforce what they don't know and they don't know how to manage the games," he told foxsports.com.
"It's not the replacement officials's fault — they are doing the best they can in a very difficult situation. For all of those who say the integrity of the game isn't being compromised, I disagree.
"I'm not taking sides. I'd just like to see the NFL and the real referees get back to the table and get this solved," said Pereira.
Media reports said the league and the referees association (NFLRA) had met in recent days but were still a long way from reaching a deal.
While criticism of refereeing decisions is nothing new in a sport with complex rules, the level of mistakes has inevitably risen this season with the stand-ins, leading to a new-found respect for the regular officials.
"As far as the old refs and the replacement refs, it's a case of you never know what you've got till their gone," said Hall of Famer Deoin Sanders on the NFL Network.
Coaches seem more willing to get in the face of officials while players are also taking advantage of the perceived weakness of referees with many more incidents of pushing and shoving, and worse.
The players, through their union the NFLPA which also fought a bitter lockout battle with the NFL last year, are also concerned about diminishing safety with the replacements.
The union's executive committee released a letter on Sunday that criticized the league in blunt terms.
"Your actions are looking more and more like simple greed," they told NFL owners.
"Your decision to lock out officials with more than 1,500 years of collective NFL experience has led to a deterioration of order, safety and integrity," added the letter which was signed by eight players including quarterbacks Drew Brees of the New Orleans Saints and Matt Hasselbeck of the Tennessee Titans.
"This affirmative decision has not only resulted in poor calls, missed calls and bad game management but the combination of those deficiencies will only continue to jeopardize player health and safety and the integrity of the game that has taken decades to build."
The letter asked the owners to end the lockout now.
Neither the NFL nor the NFLRA are publicly discussing the status of talks over the new collective bargaining agreement (CBA).
(Editing by Tony Jimenez)