The Washington Capitals added a corner man for their playoff fight yesterday when they acquired 28-year-old left wing Greg Polis from the New York Rangers for the $100 waiver fee.

There was bad news as well. Defenseman Pete Scamurra's left knee will undergo surgery for ligament damage Wednesday at Arlington Hospital and he will be lost for the season. Scamurra was tripped in the closing moments of a 4-1 victory at Detroit on Jan. 6.

Additionally, defenseman Leif Svensson, forced out of Sunday's 5-3 victory over Vancouver with a sprained left ankle, will not be available for tonight's battle with the New York Islanders at Nassau Coliseum (WDCA-TV-20 at 8 p.m.).

Whetere Polis will play against the Islanders, who have not lost at home this season, will be determined following a meeting this afternoon with General Manager Max McNab. Polis has not played since Dec. 16.

Polis, 6 feet and 195 pounds, is making a comeback following surgery on his right knee. He started the season with the Ranger's New Haven farm club in the American Hockey League, collecting three goals and three assists in 11 games. After his return to the Rangers, he scored one goal and one assist in six games.

"They've got a scoring machine going in New York that won't quit, so they gave him an opportunity to stay in the league, as we did with Greg Carroll," McNab said,

"We've got playmakers and producers, if we can control the corners. Playing with (Blair) Stewart and (Ryan) Walter has made life easier for Guy (Charron). (Rolf) Edberg and (Dennis) mAruk need support, too.

"Greg checks out physically. He will give us a little strength and ability where we are a little shy."

Polis earned a reputation as a difficult man to move out of the slot during 3 1/2 seasons in Pittsburgh.He totaled 88 goals, including 30 during the 1971-72 season. He was a No. 1 draft pick of the Penguins in 1970.

Dealt on to St. Louis and after to the Rangers, Polis recorded a 26-goal season with New York in 1974-75. He has 161 goals in an NHL career that spans 568 games.

Polis' finest moment came on Jan. 30, 1973, when he won a car as the outstanding player in the NHL All-Star Game, scoring two goals in Madision Square Garden.

Scamurra underwent surgery in April for calcium deposits in his leg and had enjoyed his best season. He elected to have an operation on the knee when he learned that it was the only way it could be tightened properly. Had it been placed in a cast, by the time the recuperative period was over, the season would have ended, too, and the kness would still have been loose.

Svensson's ankle was sprained on both sides and it is questionable whether he will be ready in time for Friday's home game against Detroit.

The Capitals will use four forward lines and five defensemen -- Robert Picard, Rick Green, Gord Smith, Gordie Lane and Yvon Labre -- against the Islanders, whose 29-5-9 record is best in the NHL.