I agree it will be a tough game; and, while I am someone who obviously loves reviewing and compiling stats/data, I am also firmly against treating statistics as anything other than good predictive information ... it's not gospel. In a funny example of how sometimes stats just don't help you all that much, consider that Xavier averages 39.1% from three on the year, and Marquette allows opponents to shoot 31.8% from three. Below are Xavier's three-point shooting percentages in their three games vs. Marquette, lol:
31.6% vs. Marquette on 12/21 (L 70-72)
11.8% at Marquette on 1/18 (W 59-57)
47.8% vs. Marquette in BET on 3/13 (L 87-89)
So they shot almost 70% below their average in the one game they won, and they shot 22%+ above their average in the game they most recently lost.

I don't know enough about Marquette to know if they are a good comparison to us in ways other than NET/KenPom rankings, but I do still think that if we play good enough defense to limit Xavier's threes and can make a decent number of our own shots, we will win.