The Detroit Lions had a bit of a salary cap issue with lots of big contracts flooding them this season after so many high draft picks under the old salary rules. Fortunately, a couple of players have re-structured their contracts to try and mitigate the problem a bit.
Both Matthew Stafford and WR Nate Burleson both restructured their deals, as reported by the Detroit Free Press, in order to help the Lions open some space up for once free agency hits. Ndamukong Suh helped as well, restructuring the last three years of his contract.
The Lions have a couple of needs that free agency would be helpful to fill, so the cap space they cleared will likely be put to good use. Cornerbacks and offensive tackle depth come to mind as possibilities.