Brady – who is the most successful player in NFL history with seven Super Bowl rings – is preparing for his 22nd season at the age of 44.
The veteran quarterback led the Buccaneers to glory last season before undergoing knee surgery, having earned Super Bowl MVP honours and a contract extension in Tampa.
Tampa Bay open their season against the Dallas Cowboys on September 9 and Brady has no plans to retire just yet.
"I'll know when the time's right. If I can't … if I'm not a championship-level quarterback, then I'm not gonna play," Brady told Peter King's Football Morning in America.
"If I'm a liability to the team, I mean, no way. But if I think I can win a championship, then I'll play."
Brady added: "I love playing football. [Offensive coordinator] Byron Leftwich said something really good the other day: It's a very simple game that's so hard to execute.
"It's a totally imperfect game that you're trying to do as perfectly as possible. Every day I come out trying to do it. I'm hoping this is my best year."
Brady – in his first season with the Buccaneers after 20 successful years at the New England Patriots – claimed his seventh Lombardi Trophy as Tampa Bay became the first team in NFL history to win the Super Bowl at their home stadium, ending the Kansas City Chiefs' hopes of retaining the title in a 31-9 rout.
He threw for 4,633 yards and 40 touchdowns with 12 interceptions, his passer rating of 102.2 his highest since his MVP season of 2017 (102.8).
Only Deshaun Watson and Patrick Mahomes had more completions of 20 yards or more than Brady's 63 as he experienced a revival as a downfield passer in Tampa.
In the playoffs, he helped the Bucs come through a gauntlet, winning three games on the road to get to the Super Bowl.
By defeating Mahomes and the Chiefs, the Bucs became the first team to win three games against former Super Bowl MVPs in the same postseason having also seen off Drew Brees and the New Orleans Saints and Aaron Rodgers and the Green Bay Packers.