Quarterback Brock Purdy, who helped lead the San Francisco 49ers to a 33-17 victory over the Miami Dolphins on Sunday, was eight years old when journeyman quarterback Josh Johnson entered the NFL with the Tampa Bay Buccaneers in 2008. According to ESPN's Adam Schefter, the 49ers are signing Johnson to be Purdy's backup for the remainder of the season.

The 49ers have lost two starting quarterbacks this season. Trey Lance went down with a season-ending ankle injury during Week 2. Garoppolo suffered a broken foot against the Dolphins and will undergo season-ending surgery.