Still led by star striker Didier Drogba and MLS defender of the year Laurent Ciman, the Impact have made only a handful of changes from the side that reached the Eastern Conference semifinals last season.
They at least hope to take another step forward in 2016.
“I said last year I thought we could win the cup,” Bush said Tuesday.
“I still believe that, given a bounce here and there, we could have done it and we can do it this year.”
The Impact, who were to leave for Florida on Tuesday night after opening training camp with two days on artificial turf at Olympic Stadium, have most of their key players back, including Bush and the entire back line of Ciman, Victor Cabrera, Donny Toia and Ambroise Oyongo.
Holding midfielder Marco Donadel is back, as are attacking midfielders Ignacio Piatti and Johan Venegas.
Midfielders who were in and out of the starting eleven like Patrice Bernier, Dominic Oduro, Calum Mallace, Kyle Bekker and Eric Alexander are also back, as are defenders Hassoun Camara, Wandrille Lefèvre and Eric Miller.
WATCH: Montreal Impact camp starts
Gone are free agent midfielders Justin Mapp and Dilly Duka as well as veteran Nigel Reo-Coker, who was dropped to clear salary cap space.
The only newcomer, other than recent draft picks, is 21-year-old offensive midfielder Lucas Ontivero.
“We’ve shown that when we play at that level we can be a top team in this league,” said Bernier, the team captain.
“Now we have to build one block more. Eighty-five per cent of the group is back. Everyone’s psyched at the possibilities of what this team can do.”
A year ago, the Impact were coming off a disastrous 2014 campaign that saw them finish last overall with only six wins in 34 games.
There were wholesale changes, including an all-new back line.
But they started the season with a thrilling run to the CONCACAF Champions League final, even while getting off to a slow start in MLS play.
There was another high in the final two months, when former Chelsea star Drogba was signed and averaged a goal per game while lifting the Impact to third place in the Eastern Conference.
They set team MLS highs with 15 wins and 51 points.
This time, there is no CONCACAF distraction.
“We need to guard against being complacent and thinking that it’s just going to be a smooth transition from last year to this year,” said Bush.
“Last year, from day one we knew we had something to prepare for. This year we don’t have that. I think we have the guys to set the tone in the locker room and we’ll be able to concentrate on exactly how we want to play this year, instead of just trying to integrate new players.”
Mauro Biello, who replaced the fired Frank Klopas in late August and took the team to a 7-2-2 finish, is back with a revamped staff picked from within the organization.
It is low on MLS coaching experience, however, but Bush said that may not be a bad thing.
“The guys we have now have fresh ideas and a great mentality and energy,” he said.
“They get along well and that’s important. The first month or two will be most important for the leadership group. We’re going to have to set the tone with how much energy we bring. They lack experience in dealing with professional players and it might be on us to confront guys in certain situations until they’re comfortable with it.”