Ten days before the start of the National Football League season, Commissioner Paul Tagliabue said yesterday he still does not know where the Raiders will play their opening game against the Denver Broncos -- Los Angeles or Oakland.

Asked yesterday where he thinks the Raiders will start the season on Sept. 9, Tagliabue said: "In a stadium someplace. . . . I don't really know the answer to that."

There have been several reports during the last week that the Raiders will play some or all of their games in Oakland Alameda County Stadium, the franchise's home until moving to Los Angeles in 1982. But Raiders owner Al Davis and his assistant, Al LoCasale, have firmly denied any such plans have been finalized.

During a conference call with reporters, Tagliabue was asked where, as commissioner, he would like to see the Raiders play. He said, "The league was of the view 10 years ago that the city of Oakland and the Raiders had a tremendous relationship."

The NFL took Davis to court, unsuccessfully, over that move. Oakland has approved a controversial plan that would cost many millions of taxpayer dollars to lure the Raiders back and improve the stadium. And one prevailing thought is that the Raiders ought to move now, instead of playing in a largely empty Los Angeles Coliseum until their lease expires after the 1991 season.

"I've spoken to Al Davis a number of times and he's been trying to keep me abreast of developments with Los Angeles and Oakland," Tagliabue said. "Obviously, it would be better if the Raiders' location was nailed down right now."

Tagliabue indicated that moving now, this close to the season opener, or even during the season would be disruptive to the entire league. However, he also said that the club's "lame duck" status in Los Angeles, where the crowd barely fills half the seats, also is troublesome to league officials.

Scheduling would not be a problem for opposing teams or television networks. NBC, which televises AFC games, would rather have the Southern California market open to show other games and would like having the sold-out games in the Bay Area, Tagliabue said. The Broncos already have made two itineraries -- one for Los Angeles, the other for Oakland.

"My only hope is that it gets resolved," Tagliabue said, so that the Raiders can devote full attention toward putting a championship-caliber team on the field. He described his role in the negotiations as "on the margin. . . . Until something is presented to me, my role is on the margin. . . . The league thought there was not ever a case for the team to leave Oakland based on the way it was supported by the community."

In other NFL news, Tagliabue indicated he and other league officials were pleased with new rules that have shortened preseason games by an average of 14 minutes compared with last year's preseason games. The average time of last year's preseason games was 3 hours 7 minutes, compared with 2:53 going into the final week of this preseason. The number of plays is down by approximately 15 per game.

The commissioner said the league may modify the newly adopted rule that has the game clock start when the ball is spotted. This week, field officials may make an exception, starting the clock when the ball is snapped -- only after kickoffs. Tagliabue said that modification would add about 80 seconds and three to five plays to each game.

The NFL, he said, was hoping to reduce games by nine to 10 minutes (instead of 14). "That's the kind of fine-tuning we're looking at," he said. "Our concern was as much the pace of the game as it was the length of the game. . . . If we can make the length of the game nine to 10 minutes shorter {than last year}, we will have achieved our objective."

He said some minor "administrative" tinkering could help in those stadiums (like RFK Stadium) in which assistant coaches are having a hard time getting to the dressing room for skull sessions, now that halftime has been cut from 15 to 12 minutes.

Also, Tagliabue said the league is considering adding yet another international preseason game next year, and that the NFL has had talks with contacts in Spain, Italy and the Soviet Union.