The first name of Toronto Star city editor Lou Clancy was stated incorrectly in a Sports story Thursday.

One of the hottest-selling souvenir items at Exhibition Stadium is a version of the familiar "I Love New York" button, only here there is added in smaller lettering, " . . . in second place."

It is about as far as the courteous and cautious partisans of the Toronto Blue Jays seem willing to go to express their resentments toward the Yankees, whose fans crassly booed "O Canada," the national anthem, when Toronto played in New York earlier this month. The demure little amendment to the button is also about as far as the fans here seem willing to let their wishes soar as their league-leading team takes a run at the American League's East title.

"Pennant fever is setting in," 15-year-old Glen Corneil said last night as he hawked Blue Jays game programs outside the stadium. But it is an odd strain of fever, one that lifts the Canadian fans' customarily polite but frosty demeanor by only a couple of degrees, and it comes with certain side effects causing anxiety and tension.

So long accustomed to faithfully supporting losers in hockey, soccer, Canadian football and baseball, the fans here seem not to know how to handle the previously almost unimagined possibility that their team may go all the way. Their reaction is to dwell on the dashed hopes of another Canadian team, the 1981 Montreal Expos, who won the National League East but lost the NL pennant to Los Angeles in five games.

Even the Blue Jays players aren't getting excited. They seemed relaxed Tuesday night after their 6-2 win in the first of three games against the Boston Red Sox, but Monday the mood in the locker room after they had defeated the Milwaukee Brewers, 5-1, was almost funereal.

Off in a corner of the locker room, pitcher Jim Clancy looked positively dejected, giving no indication whatsoever that he had just made an impressive six-inning contribution to the Blue Jays' victory in his first game since suffering a shoulder injury in July.

"We really don't want to wake anybody up," he said softly. "Everybody's going to go out there . . . If we win it, we win it. If we don't, it wasn't meant to be."

There was only the trace of an edge to the voice of longtime Blue Jays fan Mardi Puttick as she patiently tried to explain why there is virtually no outward expression of mass enthusiasm here.

"We're not as vocal as the people in New York, but you can almost taste a winner," she said as she and her husband Bill, a printer, lingered over a shared bottle of beer in a tavern near the stadium before they headed off to the game. "In the conservative Canadian manner, the excitement is there; it's simply not as verbal as the Americans'. I would like to think we would never boo the American national anthem."

In the days after the incident in New York, Blue Jays fans lined up here to buy tickets to the last two games of the regular season, against the Yankees, causing a sellout of unprecedented swiftness.

Players and fans here say it was not just the booing on the first night that they found appalling ("It kind of fired us up. It was like we were from some kind of communist nation out to beat them," said outfielder-first baseman Willie Upshaw, who, in fact, is from Blanco, Tex.). On the next night, they said they found doubly insulting the announcer's attempt to quiet the New York crowd by reminding them that Canada was a friendly ally whose ambassador in Tehran had courageously safeguarded six U.S. diplomats during the Iranian hostage crisis.

The last straw for Canadians came on the third night of the series, when the anthem singer, Mary O'Dowd, haltingly charged into "O Canada," then forgot the words. Later, O'Dowd apologized for muffing the anthem and said she wished she had the opportunity to sing it again.

Then a rather strange thing happened. Five newspaper and broadcast groups here began a bidding war to pay her expenses to come to Canada.

"We decided we would give her another chance," said Bill Clancy, city editor of the Toronto Star, who insists his newspaper was the first to make the offer. But the Blue Jays management this week squelched the plan, announcing other singers had already been lined up.

The Blue Jays organization has other, more pressing matters to which to attend, such as the work already started on a special press auxiliary stand in anticipation of the herds who will flock here should its team gain the playoffs. Bill Puttick worries that the outmoded open-air stadium, built for Canadian football, will cause Canada to be a laughing stock in the United States when it is subjected to constant exposure on network television.

But never mind the stadium. Never mind that it will probably be freezing or worse here in October. Never mind that the roster of what could be the first Canadian team to reach the World Series is made up of 21 U.S. citizens, four Dominicans and not a single Canadian. For this city is truly excited, even if the residents tend to express their feelings in a somewhat quirky, low-key way. Attendance has averaged nearly 30,000 and the Blue Jays are Topic A around town, although the talk is quiet.

Local political columnist Dalton Camp finds this muted manner ironic and amusing. "Had Canada's sporting forefathers suspected we would one day become a nation of baseball fans," he wrote the other day, "they would have developed an improved Canadian version of the game with five bases, two shortstops and a smaller ball . . .

"As Canadians, what can we bring to this remarkably un-Canadian occasion, other than our curiosity?" he asked. Perhaps part of the answer to that is the deeply ingrained Canadian feeling of being in the shadow of a brash and powerful neighbor, a relationship they are fond of saying resembles the mouse finding itself in bed with the elephant.

As the Blue Jays have moved closer to the AL East championship, the enthusiasm has spread beyond Toronto and Ontario Province -- all the way to Vancouver on the west coast and to Halifax on the east. There has been a growing demand for televised games, which have even been beamed north to the Arctic, gaining an audience among the Eskimos. All Canadians take pride in the Blue Jays' 1985 record or, as they like to put it here, the team's excellence at "someone else's national pastime."

"You Americans, I know what you're going to do," cab driver Wyndham Wise said. "As soon as we win the World Series, you're going to declare it unconstitutional."