Peseiro's men go into their concluding Champions League Group H game knowing that with them already guaranteed to finish in fourth place, they can neither progress to the knockout rounds of the tournament this term nor gain entry to those of the Europa League.
As far as the coach is concerned, though, it is still important that the Portuguese side defeat their Turkish opponents at the Estadio AXA.
"In all aspects, it is important to win," Peseiro said.
"In terms of financial issues it is important, but we also want to prove our worth.
"We had the capability to continue in the Champions League or Europa League and we have to do our best."
Braga have lost four of their last six games in all competitions but beat Porto 2-1 in the Portuguese Cup last Friday - five days after a 2-0 league defeat to the same side - and Peseiro insists his players are not feeling too down.
"If we were so demoralised as people say we would not have been able to play two good games against Porto," Peseiro said.
"The first game was balanced, much more so than people said.
"Then the victory gave us confidence and a win tomorrow [Wednesday] would help strengthen that process."
Giving his assessment of Galatasaray - currently second in Group H, level on seven points with third-placed Cluj and unable to catch leaders Manchester United - Peseiro said: "They are a good team and I like the football they play.
"They like to take the game and play attractive football.
"In Turkey (where Braga won 2-0) we wanted to attack more, but our opponent was strong. We are a team that wants and likes attacking football."
Galatasaray need to match - or better - Cluj's result to go through to the last 16, but coach Fatih Terim does not think that will be a straightforward task in Portugal.
"To me the best solution is to get through, that's the most important thing, no matter the result," he said.
"But tomorrow's [Wednesday's] match will be much more difficult than in Istanbul. Braga are playing at home, they have no pressure at all and they are playing for pride."
Goalkeeper Fernando Muslera will undergo a late fitness test ahead of the match.