It's been nearly 12 years, but Jeff Van Gundy still regrets the day he decided to walk away from the New York Knicks.

The topic came up while Van Gundy was defending Doc Rivers' breakup with the Boston Celtics in an interview with ESPN New York 98.7 FM. ESPN's Bill Simmons has been critical of the way Rivers handled his exit from the Celtics, but Van Gundy stood up for his former contemporary.

"I quit the Knicks so I know what quitting is," Van Gundy said in an interview with "The Michael Kay Show." "I did. I quit. And it's something I regret to this day. I live with it every day and I regret it. And I let my emotions come into it. And I was just emotionally spent. I made a bad decision and I quit.

Listen to the interview with Jeff Van Gundy:

"Doc Rivers didn't quit. He was allowed to pursue a better opportunity for himself. And to me, that's a significant, significant difference that everybody's glossing over."

Rivers left the Celtics earlier this week to coach the Clippers. In return, Los Angeles sent Boston a 2015 first-round pick. Some view the transaction as Rivers bailing on the Celtics as they approach a rebuild. But Van Gundy says there's a big difference between what Rivers did and what he did when leaving the Knicks in December 2001.

"Mine's worse. I live with that regret every day. Not because I view myself, quote-unquote as a quitter. I don't look at it that way. But I did leave that situation, I did quit that situation and I live with that regret," Van Gundy, now an ESPN analyst, said.

Former Knicks coach Jeff Van Gundy might prefer to have a clipboard in his hand. David Butler II/USA TODAY Sports

When asked about his reasons for leaving the Knicks, Van Gundy mentioned several factors: The team had lost to the Toronto Raptors in the postseason the previous year; Marcus Camby had to deal with the kidnapping of his mother and two sisters during the series; Patrick Ewing was traded before the 2000-01 season; Larry Johnson retired before the 2001-02 season.

"I had a great job with the Knicks. Like I said, I let momentary frustration, not even momentary, things that had been building up, this frustration, when I should have taken more time to come to that conclusion or a conclusion," Van Gundy said.

Van Gundy credited Knicks owner James Dolan for providing him with every resource necessary to succeed.

"The frustrations were real but it was certainly on overreaction and, like I said, I'm the only one to blame for that because I had a great, great job and I left it voluntarily and I still regret it," he said.

Van Gundy said he still feels badly that he wasn't able to deliver a title during his tenure as Knicks coach.

"I will always regret that I wasn't able to help those guys (his players) get what they honestly deserved," he said.

He remembers the day he walked out on the team vividly.

"I did get a good hot dog out of it because I walked from the practice facility to the hot dog stand … but that was about all I got from that stupid decision," he said.

NETS HAVE BEST STARTING FIVE IN THE LEAGUE: Van Gundy gave Nets owner Mikhail Prokhorov major credit for shelling out the money to bring Paul Pierce and Kevin Garnett to Brooklyn.

He says Prokhorov and the Nets have put together the best starting five in the NBA. Pierce, Garnett, Brook Lopez, Deron Williams and Joe Johnson will start for Brooklyn in 2013-14.

"I do think they're a championship-caliber team," Van Gundy said. "If they play well and remain healthy, which is always a challenge for an older team, I think they have the best starting unit talent in basketball."