The flying winger made his comeback in last weekend's tight 15-13 RaboDirect PRO12 victory over Edinburgh Rugby at the RDS.
And while the influential Ireland player has returned sooner from his knee injury than many expected, he insists that the whole Leinster squad will have to be step up a level if they are to win Saturday's play-off game with Ulster on Saturday.
"That Edinburgh game was my first game back from injury," McFadden told the Leinster Rugby website.
"I actually thought the guys played pretty well against Treviso and Ulster in the previous matches. It was probably a step down in our standards against Edinburgh and I think if we produce that against Ulster we'll lose.
"I just think maybe it's a good kick up the backside before a make-or-break game that we have to win against Ulster this week."
Leinster will bid a fond farewell to stalwarts Brian O'Driscoll and Leo Cullen at the end of this season, and McFadden is aiming to send them into retirement with another winners medal around their necks.
"It would be amazing to finish for those guys on a winning note," he added. "For me personally as well, all these opportunities are few and far between in your career and you've just got to try and get as much silverware as possible when you get the opportunity."
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