The No. 3 overall pick of the 2021 NFL draft is now No. 3 on the San Francisco 49ers' depth chart at quarterback.

Sam Darnold has been named the 49ers' backup QB ahead of Trey Lance in the battle of former third overall draft picks.

Kyle Shanahan's decision to go with Darnold as Brock Purdy's backup was reported by Ian Rapoport and Tom Pelissero of NFL Media on Wednesday.

Lance's future in San Francisco is now uncertain, as the 49ers are reportedly exploring various options with the QB they drafted just over two years ago.

San Francisco paid a hefty price to draft Lance, trading three first-round picks and a third-rounder to the Miami Dolphin in 2021 to move up from No. 12 to select Lance after the Jacksonville Jaguars made Trevor Lawrence the top overall selection and the New York Jets picked Zach Wilson.

As Jimmy Garoppolo's backup in 2021, Lance appeared in six games as a rookie before being named the 49ers' starting quarterback for 2022, but he suffered a season-ending fractured right ankle in Week 2.

In eight career games, he's completed 54.9 per cent of his passes for 797 yards with five touchdowns and three interceptions for an 84.5 QB rating. He has also rushed for 235 yards with a score.

He got the start in the preseason opener, and completed 22-of-33 passes for 285 yards with two touchdowns and a pick while being sacked four times in two exhibition games.

Darnold started the second preseason game, and has completed 16-of-22 passes for 193 yards while being sacked twice in two games.

The 49ers acquired Darnold in March to add depth at quarterback behind Purdy, who famously suffered a torn elbow ligament on the first offensive series for the 49ers in the 2022 NFC championship game.

Purdy, the final pick in last year's draft, won all five of his starts in the 2022 regular season after taking over for an injured Garoppolo in Week 13 to lift the 49ers to a 13-4 record and the second seed in the NFC. He has been cleared to start the season opener against the Pittsburgh Steelers on September 10.

Darnold was the third overall pick of the 2018 draft by the New York Jets, and hasn't enjoyed much success in his five NFL seasons.

He did put together some encouraging performances last year with the Carolina Panthers, however, throwing for 1,143 yards with seven TDs and three interceptions for a 92.6 passer rating while going 4-2 as a starter.

In 56 career games, he has completed 59.7 per cent of his passes for 11,767 yards with 61 touchdowns and 55 picks.

Since his rookie season, his 78.2 passer rating ranks last among the 42 quarterbacks with a minimum of 750 attempts.