Premier League leaders Chelsea won their first silverware since Jose Mourinho returned as manager when they defeated London rivals Tottenham 2-0 in the Wembley showpiece at the start of this month.
A hard-fought 1-0 victory at West Ham followed in the league as Chelsea made it eight games unbeaten since suffering a surprise 4-2 defeat to third tier Bradford City in the FA Cup.
That loss afforded Chelsea a rare weekend off and Cahill believes the extra time spent on the training ground could be crucial in Wednesday's UEFA Champions League last 16 contest at Stamford Bridge, with the tie locked at 1-1.
"The cup final was huge in terms of the atmosphere around the club and the dressing room," he told Chelsea's official website. "We were desperate as a team, as a squad, to win that game.
"We came through it really well and hopefully as a group we can use the positive experiences from that and try and build momentum for many more cup finals.
"We have had more time than we usually would to rest up and prepare in training for a good three or four days before the game. We've been able to really work on specific things in preparation for it.
"We know the quality of PSG and the job that lies ahead of us. It's going to be like a final, a big one-off game and we'll be ready to go out there and give it everything we have to get us into the next round."
Chelsea defeated French champions PSG in last season's quarter-finals and return to London in better shape this time around having trailed 3-1 following the first leg 12 months ago.
For big-spending PSG, the match offers the chance to finally make a statement in Europe's premier competition, having suffered last-eight defeats on the away goals rule to Barcelona and Chelsea in the last two seasons.
Former Chelsea defender David Luiz stoked the flames ahead of his return to Stamford Bridge by claiming Mourinho was not special for him - a reference to the Portuguese's 'Special One' moniker.
The Brazil international also spoke of his belief that PSG can progress, a view shared by team-mate Blaise Matuidi.
"Wednesday's match will be a very tough one against a team full of confidence," he told PSG's official website. "But we're heading there to qualify."
Head coach Laurent Blanc will have to make do without Serge Aurier (hamstring), Lucas Moura (groin) and Yohan Cabaye (thigh).
Chelsea will once more be without John Obi Mikel (knee), but Nemanja Matic should shake of an ankle injury sustained celebrating the League Cup win - despite the Serbian missing that match through suspension.
