NBA legend Jason Kidd reflects on Tim Duncan's career and how he almost joined Duncan with the San Antonio Spurs. (3:00)

LAS VEGAS -- More than 13 years later, Jason Kidd still wonders how many championships he could have won feeding the ball to Tim Duncan in San Antonio.

On the day when Duncan announced his retirement after one of the all-time great NBA careers, Kidd revealed Monday that he actually told the San Antonio Spurs he would team up with Duncan when Kidd was the most sought-after free agent in 2003.

Calling it "the biggest disappointment," Kidd said he still has nightmares about his decision to stay in New Jersey and sign a six-year, $103 million deal with the Nets, who were soon after broken up by new ownership despite having a roster featuring the key players from two consecutive NBA Finals.

"I thought I was going to be a Spur," Kidd, now the Milwaukee Bucks coach, said while watching his team during the Las Vegas Summer League on Monday. "I committed when I was down there on my visit [to San Antonio].

"On my flight home, I think I got cold feet," Kidd continued. "And sometimes I have nightmares about that. Maybe I could have won a championship or two there. But I got really lucky with Dallas and won a championship."

Kidd won his only championship in 2011 with the Dallas Mavericks. But he wonders how many more he could have won alongside Duncan, who kept Kidd from winning serious NBA hardware during his prime.

During his first season with the Nets after being traded by the Phoenix Suns in a deal for Stephon Marbury, Kidd led New Jersey to a 52-win season and their first Eastern Conference championship before losing to Shaquille O'Neal and Kobe Bryant's Los Angeles Lakers.

It was perhaps Kidd's finest season as he orchestrated a 26-win turnaround from the year before with a MVP-campaign. But Duncan got 12 more first-place votes and the MVP trophy that 2001-02 season.

The following season, Kidd led the Nets back to the NBA Finals but fell in six games to Duncan. Not long after that championship loss, Kidd flew to San Antonio for his only free-agent visit.

The point guard and his then wife, Joumana, were blown away by the Spurs' first-class recruiting pitch. Duncan spent time with the Kidd and tried to convince the All-Star point guard that the Spurs would make things work despite already having a young and talented point guard in Tony Parker.

By the end of the trip, Kidd told Gregg Popovich he was a Spur. But his family ultimately wanted to stay in New Jersey. It had been previously reported that Kidd was leaning toward or was ready to join the Spurs before making up his mind to stay. The Nets would sign Alonzo Mourning to a four-year, $22.6 million deal to help sweeten the pot for Kidd.

"Yeah, there was turbulence on the airplane," Kidd cracked of what changed his mind. "I wanted to go to San Antonio, I told them I was coming. I had to tell them that I was changing my mind and staying with the Nets. It was a day later when I had to tell them but when I got back to Jersey, when I started thinking about the process, I felt a little more comfortable staying home."

Kidd, though, would regret that decision after the Nets were sold to new owner Bruce Ratner, who opted not to re-sign Kenyon Martin a season later and reduced payroll with the main goal to move to Brooklyn.

All these years later, Duncan retires as possibly the game's greatest power forward with five NBA titles, two NBA MVP awards and 15 All-Star appearances.

"He was unstoppable," Kidd said of Duncan during that 2003 NBA Finals win over the Nets. "You talk about Shaq, I would put Tim Duncan in that same category. Mr. Fundamental, just kept things simple, he is a great teammate, a great player and a great person. When you have those ingredients in a champion, you just want to be a part of that and have an opportunity to play with him.

"But I only got to play with him in All-Star games and with Team USA. Unfortunately I didn't get to play with him with the Spurs."

Kidd wonders what could have been.

"It is something that I sometimes regret," Kidd said. "I wanted to see if I could win a championship in San Antonio."

"When you talk about Duncan, you can't say that I got cheated [out of MVP in 2001-02]," Kidd added. "Just coming to second to him was an honor in itself. The biggest disappointment is maybe not joining him, joining San Antonio and trying to win a championship when I had the opportunity as a free agent."