As Coach Gary Green of the Washington Capitals purchased a paper at a Boston newsstand yesterday, the attendant said. "You should have won that game last night."

Banging his head in mock despair, Green said, "I've been hearing that all night. I didn't need an instant replay this morning."

Twenty-eight seconds away from their sixth straight victory, the Capitals were tied by Boston, 3-3, when Ray Bourque kept the puck inside the Washington blueline, avoided two Capitals who had been thinking "empty-net goal" and scored on a 40-foot shot.

It is not the kind of game that is easy to forget. Twice earlier this season an opponent had pulled its goalie and scored in the last minute to tie the Capitals, and in neither case has the circumstance been erased from memory.

The first time it was Montreal's Rejean Houle, to complete a two-goal comeback by the Canadiens in the last two minutes. The second time the villain was Philadelphia's Bobby Clarke scoring with four seconds left after the Capitals, in similar vein to Sunday, had just failed to knock the puck over the blueline.

The Capitals must push Sunday's disappointment as far back in their minds as possible, however, because the Colorado Rockies come to Capital Centre tonight at 7:30 and Washington, tied with Detroit for 16th place, cannot afford another stumble against ghe lowly Denver club.

The Capitals' last defeat came on home ice against the Rockies March 2 and Washington has not beaten Colorado all season, having played two ties in Denver.

Although defenseman Pat Ribble will not dress tonight because of that strained lateral ligament in his left knee, captain Ryan Walter insists that he will be ready.

Walter, who twisted his left leg in a fall at Boston, limped onto the team bus yesterday, his left eye blackened and his chin cut, to be greeted by Mike Gartner, who asked, "Excuse me, are you a boxer?"

Walter has played every game this season despite a variety of aliments and Sunday, following the spill that left him flat on the ice for several minutes, he returned to make a perfect pass out of the corner to Paul Mulvey for the goal that put the Capitals ahead, 3-2, with 65 seconds remaining.

General Manager Max McNab, in praising Walter's courage, inadvertently underlined the club's thinking on Sunday's tie.

"He's an amazing kid, absolutely amazing," McNab said. "That play he made for the winner -- I should say tyring goal -- was remarkable. Under pressure delivering it right on the money. It had to be perfect, because Mulvey had no room to maneuver."

Green gave the team a day off yesterday, figuring psychological preparation would be most beneficial than physical work.

"They need a mental rest," Green said. "I'm not worried about their legs. They've all got the legs now. Last time we played the Rockies, it was right after a game in Montreal, and everybody had to get up early. They just never got going that night.

"This time they should be ready.They'd better be. I'm sure everybody read how Colorado came back from 4-0 to tie Philly Sunday. They won't need any convincing that Colorado is palying well."

If the Capitals win or tie, they will set a club record by going undefeated through seven straight games. Gartner will be trying to extend his goal-scoring streak to eight games.