I don’t think there’s an official in-season deadline, but teams in a playoff run often feel that contract negotiations can distract players from the game itself. Some teams may have their own unwritten (or written, I suppose) in-season deadlines.
What follows is my understanding of how the cap works. I think I’ve got a pretty good handle on it, but it’s by no means definitive.
Grant was in the last year of his contract. Assuming the existing contract included a signing bonus and escalating annual salaries, the cap charge for the current contract includes one year of the signing bonus and the 2006 salary. If the Saints extend Grant’s contract mid-year, they’re still on the hook for the signing bonus portion of the existing contract, but they only count the portion of the annual salary that was paid before the extension.
So if Grant signed a three year contract in 2004 for a $6,000,000 bonus and annual salaries of $500,000, $750,000, and $1,000,000, his 2006 cap charge would be $3,000,000 (1/3 of the $6,000,000 signing bonus plus the $1,000,000 2006 salary). Let’s say the Saints sign him to an extension after game 8 of 2006 - it’s a four year extension with a signing bonus of $12,000,000 and annual salaries of $500,000, $650,000, $800,000, and $1,000,000. In a normal contract situation, the 2006 cap charge from this contract (ignoring the previous one) would be $3,500,000 - $3,000,000 from the bonus and $500,000 base salary.
However, it’s a midseason extension. They’ve already paid him the $2,000,000 in the signing bonus, as well as $500,000 during the season. The $500,000 salary paid this season has to be charged against 2006, but the remainder of the bonus can be rolled into the new bonus and prorated over the life of the new contract. The 2006 base salary for the new contract will be cut as well, since he’ll only be paid for 8 games (half the season) under the new contract.
As far as I can figure, the cap charges for the mid-season contract extension would be:
2006: $3,000,000 (new bonus) + $250,000 (prorated portion of new base salary) + $500,000 ($2,000,000 of original signing bonus divided by four years of new contract) + $500,000 base salary already paid to him in 2006, for a total of $4,250,000.
2007: $3,500,000 (new bonus plus remainder f original bonus) + $650,000 (2007 base salary) = $4,150,000.
2008: $3,500,000 (new bonus plus remainder f original bonus) + $800,000 (2007 base salary) = $4,300,000.
2009: $3,500,000 (new bonus plus remainder f original bonus) + $1,000,000 (2007 base salary) = $4,500,000.