"You've got to know, first of all, the beast that you're playing," he said.
If they didn't know then, they know now.
The beast with five rings emerged from the San Antonio Spurs, and it was real. The beast that has survived for 16 years took the Staples Center court, and it was relentless.
The beast will surely one day be eliminated and eventually disappear, but it won't be easy, and it won't be pretty, and it didn't happen Wednesday night.
With the Spurs' season on the brink — heck, with their entire dynasty on the brink — they hung on for a sweat-soaked 111-107 overtime victory against a Clippers team that collapsed under the weight of its chore.
"They're a team that's not going to beat themselves, you've got to go out there and beat them," the Clippers' Chris Paul said afterward of the Spurs. "You've got to take it."
Instead, like many teams before them, the Clippers got taken. The series that could have been essentially over with a second consecutive Clippers victory is now alive and tied at one game apiece. An aging Spurs team finished the game embracing and hopping. A charged Clippers team, meanwhile, walked slowly off the floor while kicking itself.
The Clippers came back from a 10-point deficit in the final half of the fourth quarter and couldn't finish them. The Clippers had a house full of screaming fans in the Staples stands, and an injured Spurs guard Tony Parker in the locker room, and couldn't finish them.
The Clippers had a tremendous block of Tim Duncan by DeAndre Jordan to set up a potential last-gasp win in regulation, and couldn't finish them. The Clippers had the ball with a two-point lead with 11.9 seconds left, Blake Griffin lost the ball, and they couldn't finish. The Clippers had an open jumper by Paul in the final seconds of regulation and couldn't finish them.
"I missed a shot I should have made to win the game," Paul said simply
Then came overtime, and the Clippers simply finished themselves, crumbling with two turnovers by Griffin, another ball lost by Jordan, and then stumbling on what was probably the deciding overtime play, a Clippers nightmare on both ends. It was a wild missed three-pointer by Matt Barnes that became an open fastbreak layup by the Spurs' Patty Mills after the exhausted Clippers simply fell asleep. That gave the Spurs a 105-101 lead they never lost and, yes, it gets worse.
Gregg Popovich, the Spurs' mastermind coach, employed the Hack-a-Jordan in the fourth quarter and the Clippers center made only four of 10 free throws when a simple 50% would have won the game.
"We gotta finish, we've been talking about it all season long, we had the opportunity to go up two-to-nothing and didn't take full advantage of it," said Paul. "We have to execute down the stretch and that's on me."
This could have been the end of the Spurs. Instead, it might be only the beginning.
A loss here would have given the Clippers a statistically daunting two-games-to-none lead in this opening round of the NBA playoffs. Home teams that win the first two games of NBA seven-game series win that series 94% of the time, so this thing would have been essentially over.
But now, the Clippers must survive at least one of two games in San Antonio while the Spurs just keep building on their history.
Since their run of greatness began in 1999, the Spurs have never lost the first two games of a first-round playoff series. That streak remains alive.
Playing in their 18th consecutive postseason, the Spurs are 14-3 in first-round series. They now have the home-court advantage that could make that record even more impressive.
"Little things, turnovers, getting back in transition, free throws," said the Clippers' Jamal Crawford in dissecting how the Clippers failed.
Indeed, the Clippers missed 17 of 37 free throws, allowed 14 points off turnovers, and were outscored by 10 in the paint. The only thing Crawford didn't mention was Duncan, the future Hall of Famer in all his fighting brilliance, making virtually every important basket, racking up 28 points and 11 rebounds while carrying a team with three subs on the floor down the stretch.
Weighing down the Clippers was Barnes, who made just one of 10 shots, and a weak bench that performed as everyone feared, being outscored 48-17.
The Spurs aren't going to go down easily, and there is now understandable concern whether the Clippers have the depth and poise to be the team to finally finish them.
Late Wednesday night, Rivers was asked about his level of disappointment.
"Do I really have to answer that?" he said.
No, not really. That beast of a NBA champion had just answered it for him.