"I'm not trying to fill shoes," he said.
Signed in the off-season as a back-up, Harrington is now likely to start some, if not all, of the Falcons' games at quarterback in 2007 as Vick fights a federal indictment connected to his alleged involvement in dogfighting.
The NFL has indefinitely barred Vick from training camp while it investigates the charges, and Falcons owner Arthur Blank has said the only reason the team didn't suspend Vick is because the league asked Atlanta to wait until its probe is finished. To some, the team seems to be acting like Vick will never be back.
That leaves it up to Harrington, who spent five mostly forgettable years in Detroit and Miami before coming to the Falcons. Harrington, who's completed 55 percent of his NFL passes while throwing 72 touchdowns against 77 interceptions, says he's ready.
"I don't know that my role has changed, to be honest," he said after the first day of training camp. "My role when I came to Atlanta was to be ready to play."
The Falcons insist Harrington doesn't have to be Vick for things to work. The key, they said, is to get on board with the offense new head coach Bobby Petrino has brought to Atlanta.
"I believe in Coach Petrino's system, and we have to buy into it," receiver Joe Horn said.
Petrino doesn't dispute that having Harrington under center instead of Vick will change the offense. But he said it's not clear what that will mean before Petrino and his staff have time to figure out what Harrington does well.
"Then you form the offense around him," Petrino said.
Harrington shied away from a reporter's question about whether Petrino's offense - successful for several college seasons at Louisville and, before that, Auburn - could win with any quarterback.
"I think that's yet to be seen, but I do believe that it's a system set up for quarterbacks," he said.
Already, Harrington said he prefers the greater degree of freedom given to the quarterback to change things up at the line under Petrino.
"It gives a quarterback options," he said. "It puts the control in my hands, which is all I can ask."
Reach Brandon Larrabee at (678) 977-3709 or firstname.lastname@example.org.