BRIEFLY : U.S. MIGHT NOT SEND NBA STARS TO TOURNEY.

Byline: Daily News Wire Services

In response to a threatened player boycott of the world championships, U.S. basketball authorities might enter a team excluding the 12 NBA players already chosen.

A decision must be made by Friday, the deadline for submitting 24-man rosters to FIBA, the international governing body that runs the tournament.

Options include entering the 12-man Goodwill Games team, made up of college players, or a roster of CBA players and Americans playing overseas. No roster would be final, however, until 72 hours before the tournament begins July 29 in Athens, Greece.

USA Basketball's executive board will confer today or Wednesday by conference call to vote on the next move.

The 12 NBA players on U.S. team are: Tim Duncan (San Antonio), Tim Hardaway (Miami), Vin Baker and Gary Payton (Seattle), Terrell Brandon (Milwaukee), Kevin Garnett and Tom Gugliotta (Minnesota), Grant Hill (Detroit), Allan Houston (New York), Christian Laettner (Atlanta), Glen Rice (Charlotte) and Chris Webber (Sacramento).

What might have been Michael Jordan's last hurrah will definitely be the highest-rated NBA Finals in history. The 40-market overnight rating for Sunday's Game 6 was a 23.0. When national numbers are released today, NBC will top the record 17.3 set in 1993 for Phoenix-Chicago. (A rating point represents 980,000 households.)

TENNIS: Steffi Graf, a seven-time Wimbledon champion now ranked 91st in the world, received a generous No. 4 seeding for the Grand Slam tournament. Andre Agassi, the 1992 champion, also was given a boost from the All England Club. He was seeded No. 13, six spots higher than his No. 19 ranking. The draw is set for today, with the tournament starting June 22.

As expected, Pete Sampras, a four-time champion and last year's winner, was seeded No. 1 among the men. Defending champ Martina Hingis was the No. 1 woman.

The prospect of tennis' first major rule change in 25 years is stirring up trouble. The International Tennis Federation is considering abolishing the `let rule' beginning with next season, although some top players oppose the change. The rule change will be debated in July at the ITF's annual meeting in Ireland and could be voted on before the year is over.

FOOTBALL: Don Shula has joined a group including Bill Cosby and the chairman of Cablevision Systems Corp. that is trying to buy the Cleveland Browns. Shula will appear with Cleveland lawyer Larry Dolan and his brother, Cablevision chairman Charles Dolan, at a news conference today to discuss his role if the group succeeds in its bid to buy the expansion Browns.

LOCAL: Ellen Dinsenbacher has been named head varsity girls' soccer coach at Saugus High. As a player, Dinsenbacher won all-league and team MVP honors for three years at Claremont Pitzer College, and has assisted in track and cross country programs at Valencia High. Dinsenbacher is a graduate of Saugus High, where she lettered four years in soccer.