The former Jacksonville Jaguars starter passed his physical and went through a workout before coming to terms with a team in search of any help it can get on offense. Leftwich was in need of work after being released by the Jaguars, a team for which started 44 games from 2003-06.

To make room on the 53-man roster for Leftwich, the Falcons released third-string quarterback Casey Bramlet.

"As I've said for some time, we've been looking to add a quarterback to the mix since D.J. Shockley's injury in the preseason," coach Bobby Petrino said in a statement released by the Falcons. "Joey Harrington remains our starting quarterback and Chris Redman is still No. 2, but signing Byron Leftwich presented us a unique opportunity to add a veteran with tremendous experience to our quarterback group."

Leftwich wore jersey No. 7 through his collegiate career at Marshall and with the Jaguars. He won't wear it with the Falcons.

That jersey number still belongs to indefinitely suspended quarterback Michael Vick, who remains on the roster while the team tries to collect $22 million in bonuses it paid to him while, according to his admission of guilt, he moonlighted as an illegal dogfighter.

No details of Leftwich's new jersey number were released.

Leftwich is expected to participate in his first practice with the team Wednesday, and he will be reunited with safety Chris Crocker, a college teammate.

Joey Harrington, who signed a two-year, $6 million contract as a free agent this spring, inherited the starting job when Vick's playing status came into doubt. In two regular-season games, Harrington has completed 35 of 52 passes for 399 yards, but he threw two interceptions that were returned for touchdowns and no touchdown passes.

The Falcons have lost to Minnesota and Leftwich's former team, Jacksonville, by a combined score of 37-10. Harrington has been sacked 13 times in the process. Petrino said Monday that Harrington is playing conservatively and that he is holding on to the ball too long, which has resulted in some of the sacks.

Though Petrino didn't blame Harrington for all of Atlanta's offensive failures, the acquisition of Leftwich signals that the team is preparing for a change if Harrington doesn't improve his play or gets hurt and if the Falcons continue losing.

For now, Leftwich will back up Harrington and No. 2 quarterback Chris Redman. Leftwich most likely won't be activated for Sunday's home opener vs. Carolina, but that could be the last time he won't be in uniform. The former Marshall star has completed 789 of 1,344 passes for 9,042 yards and thrown 51 touchdowns and 36 interceptions.

Leftwich has been beset by left ankle injuries throughout his career but especially the past two seasons, when he missed 15 games. Drawing equal love and disdain from fans in Jacksonville - much like Vick in Atlanta - he surprisingly was released by the Jaguars at the end of preseason, months after coach Jack Del Rio named Leftwich the starter.

Del Rio, with whom Leftwich was said to have a sometimes-contemptuous relationship, named David Garrard the starter during preseason and tried to trade Leftwich, one of the team's more popular players, before cutting him.