In an interview with the Los Angeles Times' Arash Markazi, Rivers recounted the team's first meeting with the marquee free agent this summer, where an adamant Leonard told team owner Steve Ballmer he couldn't commit to the franchise without another star upgrade on the way.
"He said, 'I want to play for you,' and he pointed at me," Rivers said. "He said, 'Mr. Ballmer, I love the things you do and what you stand for, but your team is not good enough and if you don't change your team, I'm not coming.'"
Leonard didn't have any specific names in mind, according to Rivers' account of the meeting, and the Clippers eventually convinced him to put pen to paper after working out a deal with the Oklahoma City Thunder for superstar Paul George.
But as it turns out, the Clippers inadvertently bound themselves to a George-or-bust scenario due to some overzealous planning.
"We actually had a list of guys, which was a mistake, but we got lucky. We shouldn't have had a list, because then he got to choose who he wanted to play with and the assumption was that we could get them," Rivers admitted. "We didn't know if we could get anybody. We just showed him guys that we thought would match him and when he saw Paul George's name he said, 'I want to play with him.'
"We showed him everybody else and he didn't want to hear it. He just stayed on Paul George, so after the meeting, we sat down and I said, 'We got to get Paul George. I don't know how we are going to do it, but we have to do it.' We did know that Oklahoma City wanted to break their team up, so that helped, but we didn't know if we could get him."
Due to cap constraints, Leonard needed to sign his contract first before the team officially traded for George. On July 10, four days after initial reports of their agreement surfaced, Los Angeles confirmed it had signed Leonard at 12:51 p.m. ET. George was announced 21 minutes later.
Leonard, who was reportedly also the subject of interest for his previous employers the Toronto Raptors, as well as the Los Angeles Lakers, told ESPN's Rachel Nichols in July he was close to signing elsewhere before the trade for George materialized.
Rivers admits he didn't know which of the two was a more likely suitor but he was determined to keep Leonard away from the rival Lakers.
"I actually told Steve jokingly that if that happens, we're moving the team to Seattle," he said. "It was a joke, but I was actually serious about it. I really believed that."