FLOWERY BRANCH, Ga. (AP) - Atlanta needs Dominique Franks and Christopher Owens to step up at cornerback.

Starter Brent Grimes, an alternate Pro Bowl pick in 2010, had minor surgery Thursday on his right knee that will sideline him for two to four weeks. Franks and Owens say not to worry, they're ready to handle a bigger role in his absence.

The Falcons (7-4) have yet to decide if they will start Franks or Owens on the left side Sunday at Houston (8-3), but either way, both players will take plenty of snaps.

Atlanta uses a nickel scheme about 55 percent of the time, so a lot will be asked of Franks, a 2010 fifth-round draft pick with no career starts, and Owens, a third-year Atlanta veteran with 10 career starts.

It's too bad that I had to get this opportunity because of some injuries,'' Franks said Thursday.We're having to sit Grimey out and (Kelvin) Hayden out, but it really helps to be learning from those guys each week and preparing myself like I'm going to play. I'm just staying with the same routine.''

Franks and Owens have spent extra time watching film this week with Dunta Robinson, the starting right cornerback who played his first six seasons with Houston. Robinson has spoken at length about the perils of covering All-Pro receiver Andre Johnson even though the Texans have lost their top two quarterbacks, Matt Schaub and Matt Leinart, to season-ending injuries.

Houston will start rookie T.J. Yates, a fifth-round draft pick who made his NFL debut in the second quarter of last week's seven-point victory at Jacksonville. Though Yates lacks experience, Owens knows he is surrounded by great playmakers like Johnson and running backs Arian Foster and Ben Tate.

We've got to stop the big play,'' Owens said.No explosive passes. They like to take a lot of shots with their big receivers. They've got long, fast receivers. If we stop that in the secondary, we've got a chance.''

Yates completed just eight of 15 passes for 70 yards and no touchdowns last week, but played well enough in the emergency role to earn his first career start.

Now that Yates has had a week of practice with Johnson, who caught two passes for 22 yards last week after missing five games with a right hamstring injury, Owens believes the five-time Pro Bowl wideout won't need long to find some rhythm.

He's as good as it gets in the NFL, but it helps me and Dominique to be getting lots of reps in practice,'' Owens said.That's really important. When you're coming off a week without much practice and then you're expected to contribute in the game, you've just got to be ready. That's what we're paid to do. No excuses.''

Against Jacksonville, Johnson caught his 700th pass in his 120th career game. Retired Indianapolis wideout Marvin Harrison is the only NFL receiver to catch that many passes in fewer games (114), but the Falcons say Houston can hurt them with or without Johnson.

Yates will target Foster on routes and make use of a versatile receiving corps that includes Owen Daniels, Kevin Walter, Jacoby Jones and tight end Joel Dreessen.

They're going to be base it off the stretch running game, a little bit of angle blocks and then the play-action,'' Atlanta coach Mike Smith said.I'm very impressed with what they do schematically on offense. It puts a lot of stress on your defense.''

Falcons defensive end John Abraham, a four-time Pro Bowl selection in 12 seasons, knows the Texans haven't traditionally given up lots of sacks under sixth-year coach Gary Kubiak. Abraham believes Houston won't ask Yates to extend plays too often. Kubiak will want him to get the ball into his playmakers' hands quickly.

The only thing we can hope for as far as bringing pressure is maybe to get to the rookie early and get him a little shook,'' Abraham said.But after going through two quarterbacks in two weeks, they're smart enough that they're not going to try to give him the whole playbook right now.''

Without a chance to bring steady pressure on Yates, the Falcons must make sure to tackle Johnson and Houston's other playmakers early and often.

It's knowing the tendencies and what receivers like to do in certain formations and in down and distance,'' Franks said,that will give me a good jump on where I think the ball is going to go.''