Gerry Cheevers, one month away from his 38th birthday, tries to rebound from knee surgery by making his seasonal debut in the Boston nets tonight as the Bruins entertain the Washington Capitals (WDCA-TV-20 at 7:30 p.m.).

Cheevers had damaged cartilage removed from his right knee Aug. 19. The knee troubled him throughout the 1977-1978 season and forced him to sit out two long stretches.

First, strained ligaments idled him for seven weeks after he caught his skate in the ice at Pittsburgh. Then he sat out six weeks with a torn ligament suffered in a collision with Colorado's Joe Contini.

In the fourth game of the Stanley Cup final, Cheevers reinjured the knee stretching to make a save on a shot by Montreal's Guy Lafleur. It took an arthrogram in August to determine that cartilage had been torn and an operation would be required.

"We talked about surgery (in May), but we decided to wait," Cheevers said. "It was coming along pretty good. We felt we would get away without an operation. Then in July, I was coming down the stairs at the house and I missed a step. I knew something was wrong.

"Still, we tired to ease off on surgery as long as possible. We thought maybe the leg was just weak from the other injury."

Because of the delay, Cheevers missed the first four weeks of the season. The Bruins hardly felt his absence, as they have compiled a 7-2-3 record to lead the Adams Division. Gilles Gilbert, although shaky in a 7-3 loss to Philadelphia Saturday, has posted an excellent 2.79 goals-against average.

The Bruins' early-season success has been particularly remarkable because their star defenseman, Brad Park, underwent surgery Oct. 14 for torn cartilage in his right knee. Additionally, defensemen Dick Redmond and Mike Milbury have played only half the schedule because of injuries. The only defensemen to play every game have been Rick Smith and Gary Doak.

Peter McNab, son of the Capitals' general manager, is the Bruins' scoring leader with 16 points. Both McNab and reformed roughneck John Wensink have collected eight goals.

Washington, which faced Montreal on home ice last night, has never beaten the Bruins. The 20-game rivalry has produced 16 Boston victories and four ties.