This summer, more than 2,500 players will report to NFL training camps. Roughly half go in knowing their roster spots are secure. But that leaves a whole bunch more fighting for every last inch.

These are the players to whom training camp is a proving ground, a trial by fire. These are the players who work harder than everyone else, because they must.  These are the players who make NFL training camps and preseason games compelling, the guys fighting for their NFL lives.

NFL.com is following five of these players, five guys who for one reason or another find themselves “On The Fringe.”  They head off to camp in July not knowing where they might be in September, when the NFL kicks off its 2010 season.

Check out our introductory series, then follow their progress throughout training camp.