The Patriots posted an announcement on Instagram on Friday that the team begins practicing in six days, with a photo of Brady.
In response, Brady commented: "2 days actually! #earlyreporters."
That means Brady, who did not attend any of the team's voluntary offseason workouts, will report to camp Sunday.
Rookies report Sunday and veterans are required to report by Wednesday. The first practice, which is open to the public, is Thursday.
Brady, who turns 41 on Aug. 3, threw for an NFL-best 4,577 yards along with 32 touchdowns and only eight interceptions last season.