Defensemen Pat Ribble and Howard Walker were left behind in a Vancouver hospital tonight when the Washington Capitals flew here for Thursday's game with the Calgary Flames. Each player was scheduled for extensive tests over the next two days to determine whether he had suffered spleen damage during Tuesday's 3-3 tie with the Vancouver Canucks.

The Capitals paid a dreadful price for their 51st point of the season. Besides losing two of their most solid defenders, they also saw goaltender Mike Palmateer damage the ligaments of his left ankle. Palmateer, who was limping badly today, will be out of action at least a week and it could be longer. A year ago, a similar injury to the same ankle kept Palmateer out a month, and he compounded the problem when he returned too soon, aggravated it and missed another month.

To fill the holes, numerically at least, the Capitals today summoned defensemen Jay Johnston and Dwayne Lowdermilk from their Hershy farm club and ordered goalie Wayne Stephenson, who has been nursing knee and back injuries, to fly here from Washington.

The defense was suffering already, with Rick Green kept home by a severe groin pull. Paul MacKinnon, of course, is still recuperating from knee surgery and is unlikely to play again this season.

Ribble was in considerable pain following the Vancouver game, although he stayed in to the finish. He apparently was hurt when he collided with the Canucks' Darcy Rota behind the Washington net. Rota went down, while Ribble stayed on his skates but was obviously wobbly. Ribble began the game with a sore foot and sat out the last five minutes of the first period after he was struck in the left knee by a Stan Smyl shot.

Walker was injured when he went crashing into the boards and his own elbow came up under his rib cage. He was immediately rushed to a hospital. X-rays showed that neither Ribble nor Walker had suffered broken ribs.

Palmateer was victimized by a patch of ice near his crease that had been the subject of earlier repairs. He caught his skate as he reached for a shot by Curt Fraser and tore the ankle. He remained in the game a few minutes more before departing with 5:44 left in the second period.

"Fraser was going for the left side on a two-on-one," Palmateer said. "I kicked my left foot out, but it caught in a rut in the ice. It was innocent enough and I thought I'd see how it felt. But after one more save, I figured I'd better come out.

"We took a penalty, so I stayed in. It wouldn't have been fair to Davy (Parro) to have him come in during a close game on a power play. After those two minutes, I got off. There's no way you want to turn a simple injury into something that will keep you out a while. I've had that happen enough."

Besides last year's lengthy ankle problems, Palmateer earlier this year pulled a hamstring in Minnesota. He tried to play the next night, aggravated it and was out for three weeks.

Late in the game, Palmateer was hustling back into uniform, because his relief man, Parro, was speared high on the chest by Vancouver's Tiger Williams and lay on the ice for a couple of minutes. Parro eventually rose and finished the game, blocking all 15 Canuck shots in the final period to maintain the tie.

Williams speared Parro with the blade of his stick after the goalie tried to chase Williams out of his crease by slashing his ankles. Incredibly, referee Bruce Hood sentenced each player to two minutes for slashing.

The television replay clearly showed Williams in the crease, for which he deserved an automatic minor, and spearing Parro, a foul that calls for ann automatic five-minute major.

"It was an obvious spear," said Washington Coach Gary Green. "I don't know how you could call it a slash. Williams had his foot in the crease all night long and it was only called once (when he knocked Palmateer down)."

"I was tapping him good on the ankle, because he was in the crease a long time," Parro said. "I told him if he stayed there I'd keep hitting him and he finally got fed up and let me have it. It didn't hurt, it's just that a little higher and I'd have been gonezo."

Ryan Walter needed nine stiches to repair a cut on his neck after he collided with the Canucks' Brent Ashton.

It's like M*A*S*H again with this club," Walter said. "I can't complain -- nine against nine. That evened out."

Defenseman Jim McTaggart had an icebag on his left ankle and a purplish welt on his neck, two of six areas he pointed out where he had been struck by pucks during the game.

Jean Pronovost was bothered by a bruised tailbone, although he was too busy celebrating Tuesday's birth of his first daughter, Sarah, to complain about the pain.

Both Johnston and Lowdermilk will make their NHL debuts Thursday. Johnston, 5-foot-11 and 195 pounds, was a third-round selection in the 1978 amateur draft. Lowdermilk, 6-0 and 200, was obtained from the New York Islanders in November. He played junior hockey with Walter in Seattle.