The 30-year-old forward re-signed for the club on Friday, shortly before the Steelmen were drawn against Russian outfit Kuban Krasnodar in the third qualifying round of the Europa League.
Motherwell exited the qualifying stages for both the Champions League and the Europa League at the first hurdle last year, at the hands of Panathinaikos and Levante respectively.
But McFadden is hopeful they can progress further this time around with a bit more self-belief.
He said: "It's going to be tough. Regardless of who we got in the draw it was going to be a tough game.
"But I think we've got to believe we can win the game.
"We need to go there and play to the best of our ability and hope it's good enough.
"They are in Europe so they must have had some success last year and they will be strong.
"But we must believe we can win. We are not here for fun; it's not a day out.
"The manager has brought in some really good players and we have to have confidence that we can win the game."
McFadden has no fears about Well's domestic campaign suffering if they do enjoy an extended run in Europe.
He added: "We are professional players, it's our job, and we want to play in as many big games as we can.
"We've got to try to get into the next round. No matter who we get in the next round, we want to try to get into the group stages.
"We want to do things we've not done before. We want to progress.
"The league form might suffer but it might not.
"You've got to do the best you can do in every game you play in."
McFadden penned a one-year deal after enjoying a successful return to Motherwell in the second half of last season.
His capture was welcomed by boss Stuart McCall, who said: "He's still very hungry to succeed, not only here, but on the international stage as well.
"It's a great acquisition for us."
Click here for completely free £10 bet with Sky Bet