This is gonna be a tough match up. Arlovski needs to stay off the mat because Nelson is a better grappler then him.
If Andrei keeps it standing but also keeps putting pressure on this will be a great win for him.
BTW If he wins this he will be 5-0 in his last 5 with wins over Pe de Pano, Werdum, O'brien, Rothwell, and Nelson. Even though he didn't look good in a number of those fights those are real good names to have wins over. I think Andrei would have to be considered the #3 HW behind Fedor and Nogueira with a win.
Although Barnett's had a good year to.