How Brock Purdy performs Sunday could go a long way toward determining Tom Brady’s future.

There is the unlikeliest sentence ever written in the history of NFL coverage.

The 49ers are in a unique situation for a potential Super Bowl winner in that they could have any of at least four different starting quarterbacks when the 2023 season opens. The rookie Purdy can continue staking his claim against the Eagles in Sunday’s NFC Championship Game and maybe in Super Bowl 57 on Feb. 12, while the two teammates who started before him — Trey Lance and Jimmy Garoppolo — watch from the sideline and the Greatest of All Time drops F-bombs on his podcast.

The 49ers’ situation isn’t analogous to the Broncos turning to Brian Griese in 1999 after John Elway retired on top or turning to Trevor Siemian in 2016 after Peyton Manning retired on top. It’s also not the same as when Neil O’Donnell left the Steelers for a big free-agent deal in 1995, or when the Vikings moved on from Joe Kapp in 1970 and the Ravens moved on from Trent Dilfer in 2001 after their final starts were in Super Bowls.