Typically, what the Phins like to do is have a guy restructure by converting a portion of his salary to signing bonus. That way, they lower said player's cap number and create cap space THIS year. But it also raises that player's cap number for the future, since....as we now know....signing bonuses are prorated annually over the duration of the contract.
For example, Here's an example of the final three years of a large contract I signed with Team FinHeaven. The columns, from left to right, represent my base salary, signing bonus, and total cap number.
2004 - $4 million | $2 million = $6 million
2005 - $5 million | $2 million = $7 million
2006 - $5 million | $2 million = $7 million
The team needs to create space this year so we can re-sign our Forum Linebacker, TerryTate. So, being the team player and all-around awesome and handsome Admin I am, I decide to take one for the team. I agree to convert $3 million of my base salary in 2004 to signing bonus (which, again, is prorated annually over the duration of the contract).
Here's what my contract looks like after the restructuring is done. Again, from left to right it's base salary, signing bonus, and total cap number.
2004 - $1 million | $3 million = $4 million
2005 - $5 million | $3 million = $8 million
2006 - $5 million | $3 million = $8 million
Notice how my cap number dropped $2 million in 2004. Instead of counting $6 million, I now only count $4 million. But also notice how my cap number for '05 and '06 has risen by $1 million each. That's guaranteed money that would result in dead cap space if I'm cut next year. And THAT'S the danger Clump and others talk about when you restructure, because you're pushing more and more guaranteed money into future years.