The upcoming surgery was first reported by the Tampa Bay Times.
A source close to the situation told ESPN that this was not a recent injury and that Brady, who led the Bucs to a victory Sunday in Super Bowl LV, had been planning the procedure for months. It wasn't immediately clear which knee the procedure will be on.
Brady was not listed on the Bucs' injury report all season. He was listed on the report as "not injury related" when he was given a handful of off days by coach Bruce Arians, something the Bucs also did with Rob Gronkowski, Ndamukong Suh and other veteran players.
Brady wore a brace on his left knee Wednesday during the Buccaneers' Super Bowl boat parade. But wearing the brace is not uncommon for the 43-year-old Brady, who also wears it when golfing and during other recreational activities.
Brady was named Super Bowl MVP for the fifth time in his career Sunday after passing for 201 yards and three touchdowns in Tampa Bay's 31-9 victory over the Kansas City Chiefs.
With the win, Brady has more Super Bowl titles (seven) than any franchise in NFL history, topping the six each won by the Pittsburgh Steelers and New England Patriots. Brady also became the only player with five Super Bowl MVPs; Joe Montana is second all time with three.