The Giallorossi claimed a 1-0 win in midweek to reach the semi-finals, and Garcia believes that it may help his side in the title race.
"Our destiny is not in our hands – or should I say feet – as there is another team with eight more points. We just have to win tomorrow and carry on like this, to be ready if those ahead of us should suffer a drop in form," he told reporters.
"Considering the way we lost in Turin, it was important to win this game. Being on home turf can help a great deal and we saw that with our fans. We didn't necessarily need to be reassured, but now we are even more confident that we are strong, because Juve hardly ever lose.
"This can help the team psychologically, but I don't think it is necessary anyway. Above all it proves Juventus can be beaten."
Roma are currently second in the Serie A table, eight points behind league leaders Juventus.