OTTAWA — A sea of fans in red jerseys stood up and decided it was time to do the wave.

It was partway through the third period of a close Wednesday night game between the Montreal Canadiens and the Ottawa Senators at the Canadian Tire Centre. Fans typically do this when their team is winning. Except none of those fans, who dominated the building, wore the Senators’ black and red. They were in bleu-blanc-rouge.

Unfortunately for Sens fans, this is what life at home is like when rival teams such as the Canadiens come to play. This season, especially, has been noticeable with pro-Canadiens crowds in the Senators’ last two home games against Montreal. Senators team president Cyril Leeder walked around the arena’s concourse among fans last week when the Canadiens were in town. A pair of Sens fans stopped Leeder and told him there were “too many Habs fans here.”

“It drives us all crazy,” Leeder told The Athletic. “When the ‘Go Habs Go’ chant (happened), I made a beeline out of the suite.”

The Senators have taken steps to gradually phase out invaders in favour of their own fans.

Last month, they notified season ticket holders that they’d offer them additional tickets for a select number of “rivalry games” through the remainder of the season, including the March 11 game against the Canadiens. Saturday night’s game against the Toronto Maple Leafs is one of two games available for purchase against their provincial rival, and the Pittsburgh Penguins (on Thursday), purely off the allure of Sidney Crosby and the fans who come to see him and his star teammates, is part of the offer.

The one catch: Senators fans are not allowed to sell or transfer them to anyone else.

“When it doesn’t feel like a home game in your own rink, that’s not good,” Senators vice president of marketing Peter Shier said. “And we only have 41 of those. You don’t want to give any of them away.”

This isn’t the first time the Senators have tried to keep rival fans out of the Canadian Tire Centre. Last spring, a letter was sent to Senators season ticket holders discouraging them from transferring their tickets to rival fans ahead of their first-round playoff series against the Maple Leafs. The Senators also turned off the ability to transfer those tickets. It led to overwhelmingly pro-Sens crowds during the postseason.

“I think it’s a good show of faith by the organization,” Senators season ticket holder Kevin Lee said. “When that Montreal game (in January) happened, it was all over social media, probably extended outside of the Ottawa social media sphere. It really put eyes on that. It’s nice to see the (organization) is making a true effort to encourage Sens fans to go to this game and try to bring the tide back the other way.”

Ottawa’s small but passionate fan base — ranking No. 30 out of 32 NHL teams in population size — has existed for over 30 years. Proximity to larger, more prominent fan bases in Toronto, Montreal, Boston and New York (in addition to having some of the most affordable ticket prices in the league), means Ottawa’s home-ice advantage is sometimes shared with opposing teams. In some cases, Senators fans are completely overpowered.

“It’s kind of annoying when you’re the away team in your home arena,” Lee said.

As a result, players have grown accustomed to seeing their fans in the minority at home when the Canadiens or Maple Leafs are in the building.

“We’re used to it. Playing an away game at home,” defenceman Jake Sanderson said after a Canadiens-Senators encounter in January. “It happens quite often. So, it is what it is.”

That encounter, which the Senators lost in overtime, prompted fans to voice their displeasure with the organization over the number of visiting fans. According to Leeder, the team learned that 6,000 tickets were transferred by season ticket holders. In turn, the Senators met with dozens of fans through focus groups to understand why they would sell tickets.

One fan told Shier she’d rather sell her Sens-Leafs tickets for personal safety, citing an uncomfortable atmosphere at a game overtaken by Leafs fans.

“She said, ‘I don’t want to be in that environment,’” Shier said.

But most fans are selling to take advantage of rising ticket prices. While Senators tickets are generally affordable, they’re marked up for games against marquee clubs. According to Ticketmaster, the cheapest ticket for the Senators’ regular-season finale April 15 against the Maple Leafs is as low as $139 CAD. Compare that with Thursday’s game against the New York Islanders, where tickets were as low as $46.

Depending on where a season ticket holder sits, they could make a profit by selling tickets to opposing fans thanks to Ticketmaster’s tiered price model, which adjusts prices for games based on demand.

“At the end of the day, those fans will gladly out-pay what Sens fans are willing to pay for those games,” Lee said.

The Senators still hope they can convince those fans not to sell those tickets and to maintain their home-ice advantage. But they also know that the team’s performance, as well as that of visiting teams, plays a role in the demand for tickets. Canadiens fans were the majority March 11. It was a different story when the Canadiens weren’t a playoff team in years past. Something similar may occur when the Leafs come to Ottawa today and next month.

“We don’t see the demand from Leaf fans for those games,” Leeder said. “They just stopped buying tickets.

“As their fortunes went down, they stopped buying.”

This initiative will continue into next season as well, likely accommodating more games against Original Six and other marquee clubs. The Senators are also in the early stages of developing an arena section exclusive to home fans, among the many initiatives and ideas the team is considering for next year.

Leeder and Shier know they can’t stop all visiting fans from coming to the Canadian Tire Centre. But they hope, at the very least, they can see more of the Sens’ red, black and white in their seats.

“We know people are under economic pressures,” Shier said. “So, we’re hoping to tap into that sentiment of (being) a Sens fan. ‘I need to be at these games. My team needs me at those games.’”