Hockey nuts facing withdrawal pains as the end of the Washington Capitals' season nears will be given a booster shot today when Capital Centre hosts a rare doubleheader.

The main event pairs the Capitals and Los Angeles Kings at 7:30. Earlier, at 4 p.m., the Capitals' orphaned farmhands, the Hershey Bears, will battle the Philadeophia Firebirds in an important American Hockey League contest.

The Bears' Hersheypark Arena is unavailable because it is being used as an evacuation center for refugees from the Three Mile Island nuclear mishap. So Archie Henderson, Doug Patey, Brent Tremblay, Gary Rissling, Gord Smith and Bill Riley will be given an unexpected opportunity to impress the folks who arrive early for the Capitals' game (single admission) they would like to dazzle next season in Washington uniforms.

The Capitals yesterday called up right wing Craig Patrick from Tulsa at the Central Hockey League as a numerical replacement for defenseman Robert Picard, who suffered a bruised left shoulder Sunday and will not dress tonight.

Picard's injury is not serious and it is hoped he will be ready for weekend games with Montreal and Pittsburgh. Leif Svensson, who had been seeing considerable duty on the wing, will stay on defense full time tonight.

General Manager Max McNab decided not to call up a defenseman from Hershey, since that club has only four available and on Sunday began tackling a difficult schedule that calls for seven games in eight nights.

Arne Stromberg, the Capitals' European representative, reported that 21-year-old Swedish winger Bengt Gustafsson, drafted by Washington last June, had signed with Edmonton of the World Hockey Association. The Capitals can claim him as part of the merger, but would be forced to keep him on their roster for two years.