In the NFL, players with multiple skill sets are more important than ever due to the prevalence of spread sets on offense and defenses that are required to use multiple fronts. Players who can serve many uses, such as returning kicks and playing wide receiver or playing cornerback and returning punts, are extremely valuable on 46-man game-day rosters.
On offense, these players help determine coverages. If you have a guy in the backfield who can be motioned out wide, it allows the quarterback to read coverage and determine if the defense is in man or zone. On defense, players who are versatile allow defensive coordinators more leeway in terms of blitzing and flexibility in personnel groupings. For example, a cornerback who is a good blitzer, can play on the outside and can line up in the slot on third down is able to shore up problems for a porous pass defense.
Here is my list of the 10 most versatile players in the NFL:
Coming out of college, Harvin clearly wasn't just a wide receiver, running back and returner; he was a special talent. The only questions regarding Harvin were durability and some potential character issues.
Now that he seems to have gotten his migraine problems under control, the biggest issue for Harvin is staying healthy. There is almost nothing he can't do on the football field.