Now they can count on a crowd of 30,000-plus at Olympic Stadium on Tuesday night in the second leg against Pachuca.
"As a player, there's nothing more fun than playing in front of a packed crowd, knowing you have a city behind you," defender Bakary Soumare said. "But you've got to give the fans what they came for.
"Not only a result, but a team that fights, that's committed, that's willing to change the things we haven't done well in the past. I think we have to right group of guys to do that."
They looked it last week when, despite the debilitating effects of playing at high altitude, the Impact played to a 2-2 draw at Pachuca in their first competitive match of 2015 to take the upper hand in the two-game, total goals series.
Pachuca, which will be up against Impact, the crowd and the unfamiliar setting of artificial turf in a domed stadium, is in a hole by allowing Montreal to score two away goals in the first leg. The Mexicans, who are in mid-season in their domestic league, will be playing a fourth game in 11 days.
Four-time Champions League winner Pachuca dominated with 73 per cent possession and 17 corner kicks in the opener, but Montreal used counter-attacks to take a two-goal led through midfielder Dilly Duka's strikes in the 25th and 53rd minutes before giving up two goals.
The first Pachuca goal came on a free kick from just outside the penalty area by Heriberto Olvera. Set piece defending was a problem last season when Montreal finished last in Major League Soccer. It's an area they hope to tighten up in the second leg.
"The result is good for us coming home but it's not over," said coach Frank Klopas. "It'll be a difficult match.
"We played well in moments. We created enough chances, but in some things we have to be better and sharper in the second game. We gave up a lot of corners and set pieces that we have to avoid in the second game because they have some quality in their service."
Klopas may make some changes for the second leg, but he had to like his new central defence pairing of Soumare and Belgian international Laurent Ciman. Duka and winger Justin Mapp also stood out, while Ignacio Piatti was a threat even if he is not yet in top form after off-season knee surgery.
The Impact drew 55,571 to the Big O the last time they were in the Champions League quarter-finals. They won that first leg match 2-0 over Santos Laguna on a pair of goals from the now-retired Eddie Sebrango.
Crowds dwindled last season as the team won only six of 34 league matches, but the draw in Mexico looks to have revived fan interest. About 10,000 tickets were sold in the last five days and they can expect walk-up sales.
A victory and a spot in the semifinals would help validate the team's many off-season moves and boost their confidence.
"Hopefully, we get a goal early and can control the tempo more," said goalkeeper Evan Bush. "But at the same time, if they want to keep the ball but we get up 2-0 again, we'll be fine with that too."
The Impact begin MLS play Saturday at DC United.