(Reuters) - Back in December, New England Patriots owner Robert Kraft crafted the strongest of endorsements for NFL Commissioner Roger Goodell after his mishandling of punishment in players' domestic abuse cases undermined his authority.
Goodell is "the one person that understands what's important, long-term interests of the game," Kraft said.
"Owners can have specific interests, players can - that's short-term. But the commissioner is always looking for the long-term best interests of the game."
This week, that was put to the test.
Goodell endorsed the National Football League's sanctions against the Patriots on Monday for using under-inflated balls in what is known as the "Deflategate" scandal. They included a four-game ban for star quarterback Tom Brady, a $1 million fine for the team and forfeiture of two draft picks.
Kraft, owner of the reigning Super Bowl champions, publicly seethed about the punishment, saying it "far exceeded any reasonable expectation" and called the NFL's process a "one-sided investigation."
As Goodell, 56, seeks to cement his public rehabilitation from last year's crisis, "Deflategate" is an opportunity to show his resolve to protect the game's integrity.
But it could also be a curse for a commissioner who has earned as much as $44 million a year running America's most popular sports league, testing his relationship with Kraft and other owners.
"This is the $44 million question: what effect does this have on eroding Goodell support among owners?" said Robert Boland, professor of sports management at New York University's Tisch Center.
"Robert Kraft has been one of his strongest supporters and Kraft has taken these allegations highly personally."
Goodell is walking a fine line. He handed Troy Vincent, the NFL's vice president of football operations, the authority to devise the sanctions, but made it clear he believed in them and the independence of the investigation by attorney Ted Wells.
Goodell has to show he is meting out the right punishment because he is coming off a bad record and has a reputation for being cozy with Kraft.
"He has to do that based on his perceived relationship with Robert Kraft to make sure that it is not perceived as playing favorites," said David Carter, executive director of the University of Southern California's Sports Business Institute.
The relationship showed signs of fraying in January when Kraft said he would demand an apology from the NFL if the Wells investigation could not "definitely determine" the Patriots had tampered with balls in the AFC title game. He said he was "disappointed" with the handling of the matter.
Brady is expected to appeal his punishment by the deadline on Thursday and Goodell then decides whether he will hear the case or, more likely, appoint a hearing officer of his choice. It is not clear if the Patriots will appeal as a team.
"Will Goodell try to take the public temperature and put his finger up in the air and see which way the wind is blowing?' asked Michael Cramer director of The Texas Program in Sports and Media at the University of Texas-Austin. "I think a little."
While his handling of the domestic abuse cases hurt him in the court of public opinion, Goodell has a good record of making the NFL a growing and profitable business for owners in his nearly nine years on the job.
Next week, he'll get a chance to take the owners' temperature on "Deflategate" at a meeting in San Francisco.
Editing by Frank Pingue