Potential pitfalls for top-five teams

Updated: November 4, 2011, 1:50 PM ET
By Fran Fraschilla

The teams that have landed in the top five of ESPN.com's preseason power rankings are there for a reason. In some cases, for lots of reasons. These are talented teams with no shortage of positive attributes that could lead to their making it to the Final Four by season's end.

But every team, no matter how talented, is vulnerable to falling short of preseason expectations. Here's my look at what could go wrong for each of the top-five teams:

1. North Carolina Tar Heels

What could go wrong? Kendall Marshall gets injured
Amazingly, despite all the talent Roy Williams has amassed on this Tar Heels team, the only real answer at the point guard position is Marshall. When he was inserted into lineup last season after incumbent Larry Drew II left the team, it was no coincidence that North Carolina proceeded to win 17 of its last 20 games and make a run to the Elite Eight.