FILE In this April 30, 2010 file photo, Detroit Lions linebacker Caleb Campbell pushes a tacking dummy during rookie NFL football mini-camp in Allen Park, Mich. Detroit drafted Campbell, a West Point graduate, in the seventh round of the 2008 draft, sparking debate about whether it was fair for a cadet to play pro sports while his peers were at war. The buzz seemed to make the Navy and Air Force bitter because their graduates were playing under different rules under the same Department of Defense directive. On the eve of training camp two years ago, the Lions received a letter from the Army informing them that Campbell had to cease playing football in order to perform "full time traditional military duties," until at least 2010. (AP Photo/Carlos Osorio)

Photo by: Carlos Osorio

FILE In this April 30, 2010 file photo, Detroit Lions linebacker Caleb Campbell pushes a tacking dummy during rookie NFL football mini-camp in Allen Park, Mich. Detroit drafted Campbell, a West Point graduate, in the seventh round of the 2008 draft, sparking debate about whether it was fair for a cadet to play pro sports while his peers were at war. The buzz seemed to make the Navy and Air Force bitter because their graduates were playing under different rules under the same Department of Defense directive. On the eve of training camp two years ago, the Lions received a letter from the Army informing them that Campbell had to cease playing football in order to perform "full time traditional military duties," until at least 2010. (AP Photo/Carlos Osorio)