Fran Fraschilla and Seth Greenberg like to get together to discuss the biggest topics in college basketball. This week, they provide their biggest concerns for the four most prominent preseason title favorites -- Arizona, Duke, Kentucky and Wisconsin.

Which national title contender is the most vulnerable?

Fran Fraschilla: I’m going with Arizona. As talented as Sean Miller’s team is -- and the Wildcats certainly have their share of high school All-Americans -- my concern is this: Who is going to be the go-to scorer on this team? It actually could be freshman Stanley Johnson, but I’m not so sure he’s ready to take that role on.