Safeco Field was rocking Monday as two teams opened a series that could determine which one of them will reach the playoffs. The problem: most of the cheers came from the horde of Canadians that “Brock and Salk” said appeared to outnumber Mariners fans.

The announced attendance of 34,809 Monday did not come close to filling the stadium, which has a capacity of more than 47,000. Of the attending fans, though, Mike Salk estimated 20,000-25,000 were in Blue Jays gear. The Blue Jays are Canada’s only baseball team and Safeco Field is a popular destination for fans in Vancouver, British Columbia.

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While Toronto starter Marco Estrada dominated the Mariners’ hitters through six innings and ultimately won 3-2 to move three games ahead of Seattle in the wild-card race, the Blue Jays fans swallowed the passion and energy and seemed to shift the balance of home-field advantage.

“You had an almost anti-home-field advantage last night,” Brock Huard said.

The Mariners have struggled to attract fans in 2016 despite a new ownership group and rise to playoff contention. The Mariners ranked 19th in MLB in attendance this season, averaging just under 28,000 fans per game. The Blue Jays, meanwhile, are fourth, attracting an average of 41,456 fans to Rogers Centre.

The Mariners offered $8 tickets during the previous home series against the Astros. CEO John Stanton told “Brock and Salk” on Sept. 15 that he was more concerned about filling the stadium during the playoff push than making money.

Huard said he understood why Blue Jays fans swarmed Seattle and was not bitter toward the fans of Canada’s team, but, as a Mariners fan and former a Seahawks quarterback, he was upset. And, in the future, he would like to see ticket sales limited to Canadian fans.

“I hope as this organization gets better, as this team gets better, that if you happen to have a series in September against these guys, that you limit the credit-card expenditures from Canada, just as the Seahawks did to the 49ers in the playoff game, just as other organizations have done around professional sports,” Huard said.

“As a player, I’ve been in some of those environments,” Huard added. “We were bad early with the Seahawks and it was all Cowboys fans. They come out yesterday and you hear more cheering for their home runs and strikeouts and the building’s coming to life for them and creating a home-field advantage for them? That’s pretty frustrating.”

Salk was disappointed by the Mariners fans turnout but said the Blue Jays fans kept Safeco Field from having a completely dead atmosphere and brought out the playoff environment.

“At least having the Blue Jays fans brought the Mariners fans to life so they were actively cheering and trying to drown them back out,” Salk said. “I think it might have been better. There is no doubt that it felt a bit like an invasion.”

Salk said he was more disappointed in the Twitter response from Mariners fans who seemed to have given up before the game even started.

“That’s the thing that hurt some more, honestly,” Salk said. “The fact that the Blue Jays want to come see their team, I don’t blame them. They’ve got a really good team and they were in the playoffs last year and making a push this year. But the Mariners are almost an identical team and you had the opportunity to go see them in the biggest series they’ve played at home in forever and nobody showed up.”

As for whether MLB commissioner Rob Manfred would let the Mariners limit ticket sales, Salk doubts it.

“I’m saying no way, Jose,” Salk said. “You’ve got an opportunity to bring young kids in who have never seen the game, who have come in from Canada, we’re growing the game. Baseball is in no position to be limiting anybody who wants to go to a baseball game from attending. I don’t buy that at all. If they happen to love the Blue Jays and they live in Vancouver, they don’t have a team up there and these are their three chances a year to see the team they root for?”

Listen below to what Brock and Salk called “the polite invasion” by Blue Jays fans.