They signed Dunta Robinson to a six-year, $57.5 million deal in free agency to secure one of the spots. It will be a free-for-all battle for the other starting position.
"I don't think there is any doubt that Dunta Robinson will be one of our starting cornerbacks," Smith said. "But on the other side, I think it can be up to a five-man race."
Brent Grimes, who started eight games last season, appears to be the early training camp leader. Brian Williams, who started five games in 2009, is battling back from knee surgery.
Christopher Owens started six games as a rookie. Chevis Jackson has been the nickel back for much of the last two seasons.
Also, rookie Dominique Franks has turned some heads early on.
"It's going to be an up-and-down battle," Smith said. "The depth chart will be changing every day. You'll see guys playing on the right side, sometimes on the left side and out of that group, we'll also get the nickel [back], which we consider a starting defensive player."
2. Offensive line: Smith said the starters are set. Todd McClure anchors at center, tackle Sam Baker and guard Justin Blalock are on the left side and tackle Tyson Clabo and guard Harvey Dahl are on the right side.
But the battle for the backup spots will be interesting. The Falcons have selected three linemen over the last two drafts in tackle Garrett Reynolds, guard Mike Johnson and center Joe Hawley. Also, Jose Valdez, a massive 6-6, 324 guard, has been developing nicely on the practice squad.
The top reserves last year -- guard Quinn Ojinnaka, center Brett Romberg and tackle Will Svitek -- all returned this summer.
3. Wide receiver: Smith has declared Roddy White, a two-time Pro Bowler, and Michael Jenkins as the No. 1 and No. 2 receivers. Harry Douglas is expected to claim the No. 3 spot if he fully recovers from knee surgery.
After those three spots, things get interesting.
Veteran Brian Finneran, Eric Weems and rookie Kerry Meier will be trying to hold off challenges from Ryan Wolfe, Brandyn Harvey, Tim Buckley, Troy Bergeron and Andy Strickland.
Meier, Wolfe and Harvey have been impressive in shorts and helmets. How they hold up under five days of padded practices is something else.
4. Defensive tackle: This battle won't be joine until Peria Jerry is fully integrated into practice. He's coming back from knee surgery, but is expected to be participating fully by next week.
Thomas Johnson, who started 11 games after Jerry went down, has looked good early.
Also, third-round draft pick Corey Peters has been impressive.
Jonathan Babineaux, the team's top defensive tackle and sack leader in 2009, could be facing a suspension from the league for his December drug-related arrest.
"Everybody has talked about the corner position as being our big battle, but I think with the defensive tackles, there is definitely some good competition there," Smith said.
Also, defensive end Jamaal Anderson is getting plenty of action at defensive tackle.
5. Defensive end: Out the mix at defensive tackle, the Falcons hope to improve their middle push.
If they are successful with that, they'll still need someone to step forward and take over the end opposite of John Abraham, particularly on passing downs.
Anderson figures to play end in the base defense. But returnees Kroy Biermann, Lawrence Sidbury and Chauncey Davis will get opportunities to pressure the quarterback.
Biermann had a promising second season with five sacks. Sidbury is hoping to make major strides in his second season, while Davis, entering his sixth season, is the steady veteran in the group.