Porto face the Spanish side in the first-leg in Portugal on Thursday evening.
“By this stage there is no such thing as favourites,” Villas-Boas told Uefa.com. “Both teams have equal chance of going through, so we’ll just play our own game. We have a great deal of respect for Villarreal and I really don’t know where they got the idea that we are favourites from.
“Villarreal are doing very well in fourth in the Spanish championship and therefore they’re one of the best teams in Europe. They have already been in a Champions League semi-final [in 2006] and are striving for success – if they don’t have trophies yet, they will one day.
“Villarreal play with an attacking style, they draw pleasure from doing so; as do we. It’s a privilege to have these two teams playing in this competition.”
