Tom Brady won't play Thursday

New England Patriots quarterback Tom Brady will not play in Thursday night's preseason opener against the Washington Redskins barring an unexpected late change, according to a source.

Backup quarterback Ryan Mallett will start and play extensively, the source confirmed, as earlier reported by the Boston Herald.

The Patriots' thinking is tied to the extensive work that Brady received in joint practices with the Redskins on Monday and Tuesday. The feeling is that work trumps the value of having Brady play a handful of snaps in the opener while also giving the team an extended look at Mallett, who has played sparingly in the regular season since he was selected in the third round of the 2011 draft.

"We got a ton of reps," Brady said earlier this week. "[Monday], I'd say it was probably 80 or 90 reps. [Tuesday] was probably pretty similar. Typically you don't get that in a given week."

With plans to sit Brady, it gives Mallett an extended opportunity to showcase his skills. Mallett is in the final year of his contract, and the Patriots drafted Jimmy Garoppolo in the second round this year (62nd overall) as his potential successor for the Patriots' backup job in 2015.