FLOWERY BRANCH — It's taken Dunta Robinson three games to get his wind back.

For the first time since signing as a free agent with the Atlanta Falcons in March, the seventh-year NFL cornerback is fully healthy. He missed preseason and much of training camp with a strained hamstring.

Because game conditions are nearly impossible to replicate, Robinson knew his body would need extra time to adapt. The coverage demands of covering receivers, beating blocks and tackling don't come easily, not even for a marquee player whose contract guarantees $22 million.

"I'm feeling better every week, every day," Robinson said this week. "Right now things are good. We've just to continue to stay focused."

A rarity in time of possession last week at New Orleans kept Robinson and the Atlanta defense off the field for all but 27 minutes of a 73-minute overtime victory.

Robinson didn't mind the rest. The Saints' prolific passing attack still finished with 365 yards and three touchdowns. Quarterback Drew Brees exhausted the Atlanta secondary by completing 30 of 38 passes, four of which covered 20 or more yards.

When the Falcons (2-1) host San Francisco (0-3) on Sunday, the Atlanta secondary must contend with Vernon Davis, the Pro Bowl tight end who last year tied Larry Fitzgerald and Randy Moss for the NFL lead in touchdown catches (13).

And Robinson believes receivers Michael Crabtree, Josh Morgan and Ted Ginn are talented enough to help the 49ers overcome a change in offensive coordinators this week when coach Mike Singletary fired Jimmy Raye and promoted Mike Johnson.

Though San Francisco ranks second-last with a 12.7 scoring average, quarterback Alex Smith showed flashes of excellence last year in his first with Johnson as his position coach. After regaining the starting job after the first six games, Smith had the best 10-game run of a five-year career with 18 touchdown passes, an 81.5 QB rating and a completion percentage of 60.5.

This year, however, Smith is struggling badly, and his receivers are averaging just 10.2 yards per catch to rank 26th.

"He could flip a switch at any minute," Robinson said. "He's got the personnel to make it happen. Vernon Davis might be the fastest tight end in the NFL. He's also a great blocker. Ginn brings speed on the edge, and Michael Crabtree is a very good route runner and a guy who can get open and make all the tough catches. It's going to be a challenge."

Falcons safety Thomas DeCoud knows the Falcons won't have an easy time containing Frank Gore, a bruising running back whose 7,788 yards from scrimmage trail only LaDainian Tomlinson and Steven Jackson since the start of 2005.

"He's not just a threat to hurt you in the running game, but he's also their leading receiver out of the backfield," DeCoud said. "We've given up a few big plays here and there. When we get those cleaned up, we'll be playing solid football and solid defense."