Winger Blair Stewart, the Washington Capitals' hard-luck guy of 1976, has suffered a torn ligamnt in his left knee and will undergo surgery Saturday at Arlington Hospital, and defenseman Rick Green has sprained ligaments in his right hand, which has been placed in a plastic splint.

Green, whose right wrist was broken Jan. 20 and was kept in a cast for seven months, is also scheduled for an intensive course of physical thereapy.

The one bit of good news the club received from a three man visit to the McLean, Va., office of Dr. P. M. Palumbo Jr., was improvement in center Guy Charron's left knee.

Charron suffered a slight tear in the cartilage of the knee while playing tennis last week. It has improved to the extent that he will begin jogging Saturday and skate a bit Monday, increasing his activity each day.

"It's still there," Charron said, "but it feels better. I think exercising with the weights has helped it."

Stewart was blasted into the boards Wednesday by 6-foot-6 rookie Archie Henderson. At first, it was believed he had a severe charley horse, but Palumbo's examination today revealed a torn medical collateral ligament.

Stewart will be out 10 to 12 weeks. He missed 10 weeks last year after suffering a broken leg and was eventually shipped to Springfield of the American Hockey League.

Stewart worked extremely hard all summer and earned the honor of being the fastest skater in the Capitals' camp in time trials Tuesday. The disabling check by Henderson followed a brief fight between the two.

Palumbo said Green was so anxious to return that he had done more work than had been recommended, after the last of eight casts was removed Aug. 24. Then Green jammed the hand last week, causing the sprained ligaments and additional soreness. His playing status depends on the results of the therapy.