The New England Patriots have restructured All Pro tight end Rob Gronkowski's contract to alter the team's cash expenditure. Gronkowski's contract has a four-year option, where the Patriots would have been required to pick up the extension before the end of the 2015 league year (ie: February 28th, 2016).
This option includes a $10 million bonus upfront, which would subsequently be applied pro rata to the length of the option, counting as a $2 million cap hit in each year from 2015 through 2019.
The Patriots opted to pay Gronkowski $4 million right now, reducing the future option to a $6 million bonus. This helps Gronkowski's camp because it provides additional cash up front, while also implying that the Patriots are planning on picking up his option at the end of the year.
For New England, the cap won't be affected since this is effectively just a cash advance. They're just spreading the money between 2015 and 2016.