On paper, SJU (PA) is a better team. They beat Villanova handily last year, they are ranked higher by any metric, they have a better record (5-2, wins against Notre Dame and Harvard, losses to Florida State and Creighton), and the most recent line I saw had them favored by 2.5, which means that they are essentially six points better than Villanova on a neutral court. Jeff Sagarin's line is reasonably similar.
As far as their actual on-court play, SJU (PA) is significantly better on offense than they are on defense, ranking 31st in adjusted offensive efficiency, and 76th in adjusted defensive efficiency according to Ken Pomeroy's tempo-free rankings. Villanova is 111th and 110th, respectively. It is worth noting; however that Villanova's strength of schedule has been significantly more difficult according to Pomeroy. Don't get it twisted though, this is a good offensive team, but they are not a particularly great shooting team. They are, however, a decent offensive rebounding team, ranked 50th in the nation, compared to Villanova, which is 205th. Getting defensive rebounds in this game is a necessity for Villanova.
I'm not too confident, but this is a winnable game for the Cats. The game is tonight at 7 PM on ESPNU.
Just please win, because this is like the Super Bowl for their annoying fans.