Dallas, San Antonio and Utah are improved, Phoenix and Portland are coming off surprise playoff showings, and Coach of the Decade Pat Riley is gone. Suddenly, the Los Angeles Lakers are wondering what happened to their dynasty.

After nine consecutive Pacific Division championships and coming off an NBA-best record, the Lakers are underdogs as the 1990-91 season begins."Rebuilding isn't a term a lot of people would associate with this team because almost all of the key players are back from the team that had the best record in the league last year," new coach Mike Dunleavy said.

"But in many ways we are rebuilding because of all the changes that have been made. It takes time for the guys to adjust to new sets and the new players we've added. I know patience isn't a word most fans like to hear, but it's what all of us will need for a while until we get things sorted out."

The Lakers, 63-19 last season, added free agent Sam Perkins and traded a draft pick for Terry Teagle, who is expected to replace Michael Cooper as the main backcourt reserve.

"We have the same goal we've always had - to win the title - and I don't think anyone here has lost sight of that," said Dunleavy, who makes his debut on Saturday when theLakers play host to the Spurs.

In Friday night's openers, it will be Phoenix vs. Utah at Tokyo in the first regular-season pro game outside North America; Orlando at Atlanta, Cleveland at Boston, New York at Charlotte, New Jersey at Indiana, Washington at Miami, Milwaukee at Detroit, Philadelphia at Chicago, Dallas at Minnesota, Golden State at Denver, Sacramento at the Los Angeles Clippers and Houston at Portland.

Also on Saturday, Houston is at Seattle.

The Spurs, who set an NBA record for single-season improvement by going from 21 victories in 1988-89 to 56 in 1989-90, also acquired veteran backups in Paul Pressey and Sidney Green.

But coach Larry Brown knows San Antonio will stand or fall with its starting lineup of David Robinson, Terry Cummings, Willie Anderson, Sean Elliott and Rod Strickland.

"They'll be improved after playing together for a year, learning what each other is capable of doing," Brown said.

Detroit, looking to become the first team in 24 years to win three straight championships, could open its season with Mark Aguirre replacing Dennis Rodman in the starting lineup. Rodman played only in the last two exhibition games because of tendinitis in his left ankle.

"I'm leaning toward Mark right now," Pistons coach Chuck Daly said. "He's really picked up his defensive game in Rodman's absence."