Aaron Wilson of the Houston Chronicle reported the team released Barkley on Friday. The two sides previously agreed to terms on a deal in March, but he apparently didn't show enough during the preseason to keep a roster spot.
Barkley entered the league when the Philadelphia Eagles drafted him in 2013, but he didn't receive significant playing time until last year when he was a member of the Chicago Bears. However, he failed to make much of an impact in 2016 with a 1-5 record as a starter and eight touchdowns and 14 interceptions.
The 49ers still have Brian Hoyer and rookie C.J. Beathard at the quarterback position, and Matt Barrows of the Sacramento Bee noted head coach Kyle Shanahan already knew the signal-caller rotation following Thursday's preseason game against the Los Angeles Chargers.
As Barrows pointed out, Beathard entered three preseason games before Barkley—who didn't even play in Thursday's contest. Instead, rookie Nick Mullens entered the game after Beathard.
Barkley is still only 26 years old and could provide young depth for a team's quarterback room, but it was clear by the preseason rotation that immediate playing time for the 49ers wasn't in the cards.