Kyle Shanahan reveals when Brock Purdy could make preseason debut

Darnold played the second half against the Raiders after Trey Lance got the start. He went 5-of-8 for 84 yards. This week, they’ll trade places with Darnold getting more reps with the second-teamers and Lance, who went 10-of-15 for 112 yards and a touchdown last week, working more with the third team.

Regardless of whether Purdy plays against the Broncos, it’s expected he will see some action in the 49ers' final preseason game against the Los Angeles Chargers on Aug. 25 — his final chance to face a live defense other than his own before the 49ers open the regular season on the road against the Pittsburgh Steelers on Sept. 10, a game in which Purdy is expected to be the starter.

Purdy won his first seven games as a starter before being knocked out of the NFC Championship Game against the Philadelphia Eagles in January. He returned later in the game but couldn’t throw due to his injury.

Including the playoffs, Purdy completed 155 of 233 passes (66.5 completion percentage) and threw for 1,943 yards, 16 touchdowns and just four interceptions. He had a passer rating of 114.6 or higher in five of his first seven starts.