The easiest way for the Bears to create significant room under the salary cap before the March 12 opening of free agency is to restructure the contract of eight-time Pro Bowl defensive end Julius Peppers. The Bears did so two years ago with a move in February 2011 that cleared $8.4 million in cap savings, a year after he signed an $84 million, six-year contract, the largest in franchise history. Peppers is due a base salary of $12.9 million in 2013 and has a cap number of $16,383,333 -- about 13 percent of the entire team's cap. By converting a portion of Peppers' base salary to bonus money, the Bears could spread out the cap hit over this year and the remaining two seasons of the deal through 2015 and give themselves some more operating room with NFL shopping season fast approaching. For example, if the Bears converted $9 million of his base salary to a bonus payment, they could reduce his cap hit for this season by $6 million. The NFL has not set its salary cap for 2013 yet. It was $120.6 million in 2012 and reported Monday that it is expected to move up to at least $122 million. Using $122 million as a benchmark, the Bears have roughly $11 million in cap space. That means if the team were to place the franchise tag on Pro Bowl defensive tackle Henry Melton at $8.3 million, it would exhaust most of the available space. In 2011, the Bears converted a $10.5 million roster bonus to a signing bonus, dropping Peppers' cap number for that season to $4,383,333 and creating the savings of $8.4 million. Of course, that move bumped up Peppers' cap number in subsequent years and is one reason why it is so large this season. A restructuring for Peppers, who has 301/2 sacks, two interceptions, seven forced fumbles and six fumble recoveries in three seasons with the team, isn't the only way to clear cap space. The Bears also could sign cornerback Charles Tillman to a multi-year extension. He is set to earn $8 million in the final year of his current contract and his cap number of $8 million is the fourth-largest on the roster behind Peppers, quarterback Jay Cutler and wide receiver Brandon Marshall. As reported last week, if the Bears place the franchise tag on Melton and do not restructure Peppers or Tillman, the club will have more than $40 million in cap space tied up in those three defenders and linebacker Lance Briggs.