Brady started his day with a car crash and ended it with a contract yesterday.

Brady’s four-year deal is worth $72 million, $48.5 million guaranteed, a source familiar with the deal told ESPN NFL Insider Adam Schefter. The extension will be added on to the final year of Brady’s contract and goes through 2014, when he will be 37 years old. Brady has said he wants to play until he’s 40.  The four-year extension with the Patriots will be filed with the NFL on today.

Brady, who was picked by the Patriots in the sixth round of the 2000 draft, is making $6.5 million this season in the final year of an earlier four-year, $48 million extension.

The extension begins in 2011 at an average of $18 million per year.

—Sabrina B.