IRVING, Texas -- Dallas Cowboys owner/general manager Jerry Jones stopped short Friday of guaranteeing a victory against the Atlanta Falcons on Sunday night.

But Friday afternoon, defensive coordinator Rob Ryan, in response to a question about the future of cornerback Mike Jenkins, guaranteed one.

"We got to win this week," Ryan said after Friday's practice at Valley Ranch. "We know it and we're going to."

There was no follow-up question to Ryan's answer, but the Cowboys have a challenge in front of them Sunday.

The Cowboys have lost their past seven Sunday night games. They will face a Falcons team that is 7-0 on the season and has won the third most home games in the NFL since 2008, posting a 29-6 record. Quarterback Matt Ryan is 29-4 as a starter at the Georgia Dome -- only New England's Tom Brady (26-2) has a better home winning percentage.

Ryan isn't deterred because his defense ranks fourth overall, third against the pass and 13th against the run. The Cowboys also have given up the fewest first downs in the NFL at 113.