Someone said it already - Tubby has a track record of preparing exceptionally well for games like this. Ultimately it's up to the players, but Tubby and his staff will have scouted the hell out of Butler and imparted as much knowledge as they can to our players.
In the end, Butler's offense comes down to 3 players: Hayward, Howard and Mack. Hayward is a very talented player, 6'8" SF, kind of skinny, very good shooter. I doubt he's ever seen a defensive player like DJ though. DJ will be glued to him the whole game, has superior strength and athleticism, and I in general, I think DJ owns this match-up soundly.
Howard and Mack are more concerning to me - Howard is a very strong post player. Not as tall as Ralph or Iverson, but stronger and uses his body well. Fundamental position defense and boxing out will be critical in this matchup, but my HOPE is that Sampson's length at least slows him down.
Shelvin Mack is the real X-factor though. If he lights us up, we likely will not win. He's a big, physical guard who can shoot the 3 and penetrate. Ultimately, Joseph and Westbrook will end up guarding him for the majority of the night, and if Mack gets going, we're in trouble.
So, on our side, we have DJ, team athleticism/defense, and a coaching advantage.
On Butler's side, there's Mack's scoring, a possible rebounding advantage, and scoring in the early stages of the game.
Can't wait for Thursday!