The League Cup winners were drawn alongside the Spanish side, Kuban Krasnodar and St. Gallen in Group A and face a trip to the Mestalla in their first match on Thursday.
Valencia are widely tipped to do well in the competition having performed well in the UEFA Champions League and Europa League in recent seasons.
"We are playing the top team in the group on their home ground, so all the pressure is on Valencia," he said. "This is only the first of six games, and my experience in these group stages is that the important games are your home games.
"If you win your three home games, then you are through, I think that’s it.
"This is probably the most difficult of the six games we face, so we have a lot to win and not so much to lose.
"But let’s see, I am quite confident, I don’t think the gap between the two teams right now is that big."
