The Washington Capitals' defensive corps received a one-two punch where it hurts yesterday.

Jack Lynch, slowly recovering from a December knee operation, was told that he must continue his present program of light exercise and skating, without contact, for another four to six weeks.

Gord Lane suffered a mild shoulder separation in yesterday's practice and will be idle for at least a week, making him an absentee for Wednesday's regular season opener at Los Angeles.

Meanwhile, the Capitals continue to experiment, trying to find some productive line combinations.

Guy Charron, whose three goals and five assists in five exhibitions double anyone else's point total, will center Bob Girard and Tom Rowe in tonight's 7:35 Capital Centre exhibition against the New York Islanders.

Another interesting grouping has Swedish newcomer Rolf Edbert centering Bob Sirots, longtime Charron linemate and a 24-goal scorer a year ago, along with 6-foot-4 rookie Paul Mulvey.

Mike Marson and Bill Riley, left at Hershey when the team made its four-game exhibition swing last week, will be in action tonight. If anyhting, they enhanced their chances by sitting out since most of the playing wings were undistinguished.

Marson will be at left wing on a line that has Greg Carroll at center and Mark Lofthouse on the right side. The fourth unit consists of left wing Gary Rissling, center Gerry Meehan and Riley.

"Remember Maine" is the Capitals' rallying cry tonight. Humiliated, 7-1, by the American Hockey League Mariners, the Capitals expect the psychological edge, an important item in hockey, to be in their corner for this first home-ice exhibition since 1975.

At Portland, the minor leaguers were psyched up for their confrontation with a National Hockey League club. The Capitals suffered a downer and trailed 3-0 before they realized how bad a night it was going to be.

Against the Islanders, Washington has every reason to be the team on a high. Jobs are at stake and memory informs that the Capitals have never beaten the New Yorkers. Worse, the 0-13-3 record includes five shutout victories by the Islanders in eight Capital Centre visits.

New York, coming off last night's battle with the hated Rangers, is the team that figures to show a dip in desire. There will be no dilution of talent, however, as the Islanders have promised to produce Mike Bossy, Bryan Trottier Clark Gillies and Denis Potvin for the customers who need pay only $7, $5 or $2, a scale $2.50 per ticket below regular season rates.

While trying to trim his 34-man squad to manageable proportions, General Manage Max McNab was further pressed by the need to refute Montreal-based rumors that the Canadians would obtained defenseman Robert Picard in exchange for a Care package.

Montreal must arrange a deal for three excess players by Monday or risk losing them in the waiver draft. McNab has been in contact with Montreal officials, but denied any intent to deal Picard, the Capitals' top draft pick a year ago.