Jimmy Connors, who aggravated his fractured right thumb last week has been advised by his doctor to rest for two to three weeks and will not defend his title as expected in the $125,000 Washington Star International tennis championships next week on the courts at 16th and Kennedy Streets NW.

Connor sustained a fracture of the distal phalanx of his right thumb five weeks ago when he caught the thumb in the shaft of his steel racket while reaching for backhand during a practice session in London. Connors is lefthanded, but hits his backhand twofisted.

After withdrawing from a pre-Wimbledon tournament at Queens Club in London, Connors received treatment and played with a specially-made leather and aluminum splint on his thumb. He reached the final at Wimbledon, losing to Bjorn Borg after coming back from 0-4 to 4-4 in the final set. Borg won't compete here, playing instead for World Team Tennis.

Connors aggravated the injury Friday practicing with Cliff Richey during the WCT Tournament of Champions at Austin, Tex.

"Like any fracture, it needs time to heal, so Jimmy will have no tennis activity for the next two to three weeks. He won't even practice," said Rexford Carruthers, Connors' attorney, by phone from St. Louis yesterday.

"We expect him to have an uneventful recovery. No disability of any type is anticipated. It's just a matter of taking time off and not whacking a tennis ball so that the bone and joint heal properly," added Carruthers.

The rest was ordered by Dr. Louis Vazquez of Torrance, Calif., the orthopedic surgeon who has been treating Connors, Carruthers said.

Connors was unavailable for comment.

Connors said during Wimbledon that his thumb was bruised and swollen but not fractured.He insisted repeatedly that it did not hinder his play.

"I'm sure that Jimmy wasn't anxious to convey to his opponents and the world at large that he had a fractured thumb, but that was the confilmed diagnosis in London," Curruthers said.

The withdrawal of Connors, who beat Raul Ramirez in last year's final, is a jolt to the Star tournament, but a strong field remains to battle for the $20,000 first prize on the artificial clay courts at Rock Creek Park.

Guillermo Vilas, French Open champion and winner here in 1975, will likely be seeded No. 1 when the draw for the 64-man tournament is made Friday evening.

Brian Gottfried, who won the Volvo Classic here in March and leads Vilas in the race for the $300,000 top prize in the Colgate Grand Prix, heads a strong contingent of American Harold Solomon of Silver Spring, Eddie Dibbs (ranked No. 2 in the U.S. to Connors), Roscoe Tanner, Stan Smith and Arthur Ashe.

Ramirez, Mexican Davis Cup ace and defending Grand Prix champion, is entered, as is Australian Phil Dent. They were the other runner-up Gottfried, in the French Open, the premier clay court tournament of Europe.

John McEnroe, who at 18 was thought to be the youngest semifinalist in the 100-year-history of Wimbledon, and the improving Gullikson twins, Tim and Tom, are among the promising young players striving to succeed Connors as the Star champion.