Villarreal had a good result in away games, 1-1 on Nou Camp, but that was at the beginning of the year when the catalans weren't in their best form. the "yellow submarine" received 4 goals on Mestalla, so it's very possible to see some goals today for Real Madrid.
Ok, but with these reasons I should bet on Real Madrid -1.5 or something, where's the catch? Real Madrid will miss Garay and Pepe, so the only central defender will be Albiol. Even if they have a good midfield and strong attack, they can receive today a goal. We saw Barcelona against Atletico, when they had missed a lot of players in the defense. So, I see more possible a game with Villarreal scoring than Real winning 2-0 or 3-0.
