Barcelona seem to be the most trustworthy team in the league currently. They are better against smaller teams comparing to Real Madrid. We have all witnessed that shocking point loss of Real Madrid against Mallorca indeed. Of course they can concede a goal but the interesting part was their not being able to score even one goal. Although you have very effective attackers how can't you score even once? It doesn't matter whether they have Benzema or not in a match like that.
Therefore Barcelona are highly favoured against Villarreal on paper. If we were able to see the old Villarreal then I would say Barcelona would struggle. But I don't think they will have too big problems.
Currently, almost all of Barcelona's matches in La Liga will place them as favourites, except for the El Clasico match against Real Madrid.
I definitely have a reason why it's difficult to make Barcelona the favorite against Real Madrid, it's because barcelona have only lost to Real Madrid so far this season. Madrid is the only team that has managed to beat Barcelona, and no other team has been able to do so in the last 20 matches.
But for the next El Clasico match, I hope Barcelona can take revenge by beating Real Madrid in the second leg of La Liga. Barcelona had to do it because it was a home game, but for whatever reason I think it's difficult to beat Real Madrid.
I think these time will be a time for Barcelona to take revenge against Real Madrid, looking at the performance of Real madrid that is not stable Barcelona will easily achieve a victory against Real Madrid. Real Madrid finds it tough to win small teams for sometimes now, Barcelona will take the weakness of Real madrid as an opportunity to win Real Madrid. Barcelona have a chance accept Real Madrid will try their best not allowing Barcelona to succeed to get a win.