Quarterback Pat White, who has not played in the NFL since his rookie season of 2009 with the Miami Dolphins, is taking part in a workout Thursday with coach Jim Harbaugh at the 49ers' Santa Clara practice facility.
The news was first reported by CSNBayArea.com's Kyle Bonagura and confirmed via a league source.
Starter Colin Kaepernick and reserve Scott Tolzien are the only 49ers quarterbacks under contract after a trade that sent Alex Smith to the Kansas City Chiefs.
White, 27, has not played in the NFL since the Dolphins released him at the end of training camp in 2010. White played in 13 games for the Dolphins in 2009. He carried 21 times for 81 yards (3.9-yard average) and did not complete a pass in his five attempts.
White, a second-round draft pick of the Dolphins, finished sixth in the Heisman Trophy balloting in 2007 and seventh in 2008 at West Virginia. He threw for 6,049 yards and 56 touchdowns while rushing for 4,480 yards and 47 touchdowns in his four-year career at West Virginia.
He spent a month this offseason working out with quarterback coach George Whitfield Jr. in Southern California as he attempts to make a comeback. The 49ers were among the 29 teams that attended West Virginia's pro day on March 14. White took part in an hour-long workout after the pro day.