The deterioration in their relationship reached the point of no return when Fizdale went after Gasol hard in a film session, basically dismissing the importance of Gasol’s accomplishments overseas, including as a member of the Spanish national team. That that rankled Gasol to no end should have been no surprise to anyone paying attention.
Fizdale tried to fix things with Gasol, even flying to Europe after the season to try and make it right. But Gasol was close with majority owner Robert Pera; Fizdale wasn’t. That closed off a potential area of outreach between the two. Gasol had no interest in rapprochement, a stance that Grizzlies players made clear to Fizdale throughout the season. (Caught most in the middle, per league sources, was Grizzlies veteran point guard Mike Conley, Jr., who did and does have strong relationships with both men.)
But, importantly, in his discussions with the Knicks, Fizdale took responsibility for his failures with Gasol. He didn’t blame Gasol or anyone else. As one of his chief calling cards is connecting with players, and not finding common ground with Gasol was an L he has to take.