Some of Roscoe Tanner's best friends had other plans this week. So Bjorn Borg, John McEnroe, Vitas Gerulaitis and Jimmy Connors couldn't make it to Washington.

Pardon Tanner if he sheds no tears. Their absence should make it considerably easier for him to defend his championship in the $125,000 Volvo Tennis Classic, which begins Monday and ends Sunday at George Washington's Smith Center.

At 2 p.m. today at the Regency Racquet Club in McLean, the four qualifying positions in the 32-player draw will be filled. Of the remaining 28 players, 25 were selected by their rankings in the Association of Tennis Professionals' computer-point standings and there -- Eddie Dibbs, Victor Amaya and John Austin, Tracy's brother -- were chosen as wild cards by the tournament director, Ray Benton.

Dibbs, ranked 10th by the computer and seeded third, Harold Solomon, eighth of the computer and the No. 2 seed, and Amaya should be Tanner's toughtest competition for the $21,875 first prize. Solomon won the title in 1976, when the total prize money was $60,000, and Dibbs was the No. 1 seed last year.

Tanner, currently fourth in the computer standings, last year convinced doubters that his game is more than a 140-mph serve followed by a Hail Mary if the ball is returned. In addition to this Volvo Classic, in which he defeated two-time titlist Brian Gottfried, he won the Volvo Tennis Games at Palm Springs, Calif., beating Connors in the final.

But that was kid stuff next to Wimbledon and the U.S. Open. At the All-England Club, he extended three-time champion Borg to five tense sets in the final before the Swede won his fourth consecutive title.