Phoenix ? With an offense as relentless as the Arizona heat, the Phoenix Suns are trampling the conventional wisdom about defense being the way to go this time of year.

Through two rounds of the playoffs, MVP Steve Nash and crew have taken the league’s highest-scoring average in 10 years and jacked it up nearly six points a game. They’ve done it while facing tricked-up defenses that have had more time to study them, and even though they’ve been without their third-leading scorer the last four games.

Now comes the real challenge: doing it in the Western Conference finals against the San Antonio Spurs, who are perfectly cast in the role of upholding conventional wisdom.

San Antonio has won two of the last six championships with defense. The Spurs allowed the fewest points in the league this season and recently had Tim Duncan and Bruce Bowen, their best inside and outside stoppers, receive their seemingly annual spots on the NBA’s all-defensive team.

They also come into this series well tested, having already eliminated high-scoring teams in the Denver Nuggets and Seattle SuperSonics.

“It will be a very big challenge for us,” said Nash, whose personal challenge will be topping his phenomenal second-round series against Dallas. “If we continue to show the pressure and poise we’ve shown all season, we’ll be all right.”

Both teams probably wish the series wasn’t starting for another day or two, but this matchup of contrasting styles is so compelling that ABC couldn’t wait to get it on the air.

The Spurs advanced late Thursday with a last-second victory in Seattle. They flew home Friday, saw the Suns advance with an overtime victory against the Mavericks that night, then headed Saturday to Phoenix.

San Antonio players admitted they were rooting for Dallas in Game 6, not because they wanted to duck the Suns but because they wanted more down time.

“I was at a restaurant, and people heard me cussing,” Spurs forward Robert Horry said, laughing.

The Spurs also were hoping Duncan would have more rest for his ailing ankles. He didn’t practice Saturday, and coach Gregg Popovich listed him as probable for the opener.

“We’re not going to do something to jeopardize Tim’s health or our team’s chances for success,” Popovich said. “If he can’t play, he’s not going to play. If he can play at all, there’s going to be no way to keep him off the court.”

Phoenix hoped guard Joe Johnson might return to the lineup today if he could adjust to a mask protecting the bone he broke near his left eye. However, he has seen only a prototype of the mask, and he’s not going to try to play until he gets comfortable with the real thing.

“I’m hoping to get back as soon as I can, but I’m not going to rush it,” he said.