Another disaster, another new player. Fourteen hours after they were overpowered on home ice by the Chicago Black Hawks, the Washington Capitals yesterday obtained right wing Michel Bergeron from the New York Islanders for a second-round pick in the 1979 amateur draft.

Bergeron and center Dennis Maruk, obtained Wednesday from the Minnesota North Stars for a first-round selection, will be in uniform tonight when the Capitals battle the Los Angeles Kings at Capital Center at 7:30. That Norris Division duel will be followed quickly by another, Saturday at Pittsburgh.

"This is a key weekend for us," said Washington General Manager Max McNab. "We're concerned about opportunities for scoring. We have to have a little imagination, and Bergeron has got it.

"Our starts the last two nights are totally unacceptable to us. We lack a spark early in the game. The first period against Atlanta scared me. I didn't like what I saw. And Chicago is not the kind of club that outshoots you 16-4. They play a tidy, organized game and wait for the breaks."

Atlanta had a 15-4 shooting edge in the first period as it spoiled the Capitals' home opener, 6-3. Then the Black Hawks built a 16-4 margin in the first 20 minutes en route to a 4-2 decision.

"This is a pivotal year for us and we're determined to find the answer," McNab said. "The thing to look for in a professional hockey player is consistency. There's a lot of pressure playing at home and maybe some guys are afraid of getting their noses dirty. I hope we didn't leave all our guts in Hershey. We have good prospects there but they need seasoning."

The addition of Bergeron and Maruk expanded the Capitals' roster to 29, of whom only 19 can dress for a game. The incumbent 27 were put through a 2-hour 15-minute workout at Capital Center yesterday by Coach Danny Belisle, with a full hour of scrimmaging.

"We're doing some experimenting," Belisle said. " We've got extra bodies and we're not totally settled. Some guys are progressing and some guys are standing still.

Obviously, someone standing still will find himself in the outbound traffic, because the roster must be reduced.

Bergeron 5-foot-10 and 170 pounds played only 25 games for the Islanders last year after being obtained from Detroit. He had back problems, but seemed sound during a Capital Centre exhibition two weeks ago.

Bergeron netted 32 goals for Detroit in 1975-76 and 21 the following year, when his season was curtailed after the Capitals' Ace Bailey caught him in the eye with a stick.

Although the 23-year-old Bergeron recently bought a home on Long Island, McNab reported that "he's a pro. He just wants to play." The Capitals have two second-round picks and will determine which the Islanders get, unless Bergeron reaches a specified goal figure.

Maruk checked in last night and said that, "I was a little shocked by the trade at first. I really want to stay in one place. I think I've established myself and I'd like to make one town happy."

Entering his fourth NHL season, Maruk had played in three different cities with one team: Oakland/Cleveland/Minnesota. In three years, he collected 94 goals and became a favorite of fans who chanted "Ma-roooook" whenever he touched the puck.

"They pay your salary," Maruk said. "The more people you bring in, the more you want to please them. Having the fans behind me made me want to work harder on the ice."

Maruk said he had been sharpening his defensive skills and" I try not to gamble as much, particularly on the power play. You can take chances, but only when you're playing with someone you know. You have to be sure he'll be in a certain spot or it's your mistake.

The 5-foot-8, 170-pounder was ignored by many teams, including the Capitals, in the 1975 amateur draft because of his size.

"I whipped that my first year," Maruk said. "I took checks and gave them out. I'm not afraid to get hit."

Maruk was a teammate of Bob Girard at Oakland and Cleveland, played junior hockey in London, Ontario, with Rick Green and Tom Rowe, and was a Team Canada standout last spring along with Capitals Robert Picard and Guy Charron.

Bergeron totaled 62 goals and 143 points in 1974 with Sorel of the Quebec League, only to be overshadowed by a guy named Bob Sirois (72 goals, 153 points.)