FLOWERY BRANCH, Ga. -- Falcons free safety and Bay Area native Thomas DeCoud grew up a 49ers fan. How could he not?

The Cal graduate's grandfather, John Thomas, was an offensive tackle for the 49ers from 1958 through 1967 and he kept his loyalty to the team.

But Thomas and at least most of his family members making the 3,000-mile trip to Atlanta for the NFC Championship Game won't be doing so to root on the 49ers.

There is team loyalty and then there is family loyalty.

"It's going to be fun," DeCoud said. "I've got a lot of people coming out for this game to see me against the Niners."

The Falcons need DeCoud and his defensive teammates to step up. After what Colin Kaepernick did to the Packers last weekend, few seem to be giving the Falcons a chance to slow the 49ers down.

"We've been underestimated all season," DeCoud said.

"We know we're a good defense," added linebacker Stephen Nicholas. "To us, what others say is just noise."

But the Falcons admit that the 49ers won't be easy to slow down, especially with the way Kaepernick is playing.

"He's a game-wrecker," defensive coordinator Mike Nolan said.

The Falcons have faced plenty of quarterbacks who can run this season, including Cam Newton of the Panthers twice.

DeCoud called facing the Seahawks' Russell Wilson one week earlier a "good cheat sheet" for the Kaepernick test. But the Falcons almost flunked the Wilson exam, as the rookie led the Seahawks to four second-half touchdowns and a near comeback victory last Sunday.

Wilson and Kaepernick are hardly the same, anyway. Neither are the Seahawks' and 49ers' offenses.

"It's going to be a big challenge," Falcons coach Mike Smith said. "There are some similarities in terms of what they do offensively, but there are a lot of things that are a little bit different."

Not only is Kaepernick bigger than Wilson, he's faster "You can't matchup and play match coverages or man-to-man because, when he gets into the secondary, he's a guy that can go the distance," Smith said.

But Kaepernick has started just eight games, and a plus for the Falcons defense has been forcing take-aways. They had 31 in the regular season and two against the Seahawks. Of those, 21 came on interceptions.

DeCoud had six interceptions, while cornerback Asante Samuel picked off five and strong safety William Moore snatched four.

It may be with his legs, though, that Kaepernick is most dangerous. He had a record 181 rushing yards against the Packers and he will definitely be a target when he runs the ball.

"If you get the opportunity to blow up somebody and make a statement, that's what you do," Moore said.

"Kaepernick is more of a one-read-and-go type guy, whereas Russell was using his feet to get his second and third reads to come open," DeCoud said. "Kaepernick most resembles Robert Griffin III. ... He has comparable speed to RGIII."

Moore already knows what Kaepernick can do first hand. He and linebacker Sean Weatherspoon faced the quarterback in college when Missouri played Nevada. "That dude was pretty good. He put up some yards on us," Moore said.

DeCoud, who graduated from Pinole Valley High after starting at Hogan Senior High in Vallejo, was a third-round draft pick in 2008 after a breakout senior season at Cal. He took a major step up with the Falcons this year -- ranking fifth in the NFL in interceptions by a safety.

His grandfather, now 77, was an All-Pro choice in 1966 and has had season tickets to 49ers games since his retirement. But DeCoud did most of his rooting for the team from in front of the TV.

"I think growing up I might have made it to one Niners game," DeCoud said. "All those other times, my uncles were fighting over those tickets."

Now, the family has conflicting allegiances.

"I hope they are all pulling for me, but some might have to wear split jerseys," said the Falcons' No. 28. "You know, my '2' in red and my '8' in black."

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