John Skelton and Kevin Kolb are engaged in a full-fledged quarterback competition this summer in Arizona for the Cardinals, and nobody knows which player will come out on top. The Cardinals aren't the only NFL team with spots up for grab at training camp, though.
Every team in the league enters training camp with positions that have yet to be determined. Many players will have to prove that they are the ones deserving of their coaches' trust rather than their competitors.
This is the way it goes every year.
Not surprisingly, the NFL has a high turnover rate.
Injuries and attrition eat away at rosters from one year to the next, and coaches are always looking to make their team better. This habitat of competition breeds ferocious battles in training camp that inevitably shape the landscape of every team and of the NFL, as a whole.
With that in mind, let's take a look at the biggest training camp battles happening around the NFL this summer.