If the most valuable player in the Stanley Cup playoffs were chosen today, the honor would got to a 37-year-old millionaire owner of race horses, a guy with two sore knees who wears a brace and has trouble with lateral movement, who receives heat treatment before a game and medications and ice packs afterward.

Gerry Cheevers, the Boston Bruin goaltender, deserves every decibel of those roars of "Chee-vers" that resounded across Boston Garden Sunday night, when he stopped 27 Montreal shots, six in overtime, as th Bruins won, 4-3, on Bobby Schmautz's goal and evened the best-of-seven final series, 2-2.

There are those who claim Cheevers uses his stick as a cane, but creaky bones or not Cheevers probably will be guarding the Boston net tonight for crucial game five at the Forum (WETA-TV, Channel 26 at 8 p.m.) Probably has to be the word, because there always seems to be the chance that Cheevers will suddenly collapse, unable to skate.

Cheevers kicked his right leg out farther than usual to block a Guy Lafleur blast in the first period Sunday and rolled in pain on the ice, signaling a teammate to freeze the puck. After lengthy treatment, however, he stayed in the net and performed brilliantly.

"The doctors tell me the knee is stable and that's all I wanted to hear," Cheever said yesterday, "I'm going to keep on playing. I was making my move one way, when the puck deflected off one of our guys and I had to make a second move. That's when the knee went."

Cheevers wear a mask on which he has painted stitches, the ones he would have needed to close wounds if he had been playing bare faced.Those shots to the head are something to joke about, but the knees are not.

Cheevers played only 21 games during the regular season. He injuried the right knee during an early season game in Pittsburgh, then was racked up Feb. 21 in a collision with Colorado's Joe Contini. Doctors suggested immediate surgery.

"They told me he was through for the season," said Boston Coach on Charry. "But he told me when he could hardly walk that he was coming back. I really didn't believe him."

Cheevers, declining surgery because "I would have missed the playoffs," was back on skates a month later. He was in the nets April 8 and has played 10 of the Bruin' 13 playoffs games, earning raves almost every night.

"I never had any doubts because I'm a positive thinker," said Cheevers, whose positive approach also helped lift his teammates after Montreal took a 2-0 lead in this series.

"He's the greatest money player that ever played the game," Cherry said. "He puts an atmosphere of confidence in the dressing room."

"The biggest thing is his leadership," said defenseman Rick Smith. "His competitiveness instills fight in every player. It instills confidence in everyone."

"It's like having another defenseman back there," said Brad Park. "He handles the puck so well and the way he keeps talking during the games keep you alert."

Cheevers was the No. 1 goaltender in Boston's Stanley Cup years of 1970 and 1972, then he grabbed a potful of money for joining the Cleveland Cursaders of the World Hockey Association. He returned to Boston in February 1976 and has since banked a lot more dollars, in the $1.2 million syndication of his colt, Royal Ski, a winter book Kentucky Derby favorite in 1977 that developed viral problems.

Why would a man with a big bank account and big physical problems continue, at age 37, to stop pucks on hockey rink?

A hot goalie can substantially reduce the odds for a hockey underdog and Cheevers is hot. The heavily favored Canadiens were wondering yesterday what kind of reception they would get tonight from their highly critical fans. One thing is certain positive or negative, the nois will not achieve the pitch or sincerity of Boston's raucaus "Chee-vers."