IRVING, Texas -- When Rob Ryan showed up as the Cowboys’ defensive coordinator last year, he promised to have the No. 1 defense in the NFL.

Three games into the 2012 season, he has it.

“It’s going to be big if we can get it after 16 weeks, that would be good,” Ryan said. “We’re happy where we are. The guys have been working hard. We're not ashamed of being No. 1, that’s where you want to be.”

The Cowboys are allowing 250 yards a game and are second in the NFL in pass defense, giving up 137 yards a game. Quibble if you want that the Cowboys have played against Seattle rookie Russell Wilson and an overmatched Josh Freeman in Tampa Bay, but they held Eli Manning to 213 yards in the season-opening win against the New York Giants.

“I haven’t done anything,” Ryan said. “I think all of our players and coaches have. We’re working hard. Look, we want to have a great defense and that’s the way it is. We’re excited where we are but more excited about where we’re going.”

While the Cowboys made upgrades at cornerback in Brandon Carr and Morris Claiborne, nose tackle Jay Ratliff has yet to play this season because of a high ankle sprain. They have also played without starters in defensive end Kenyon Coleman and safety Gerald Sensabaugh and lost safety Barry Church to a torn Achilles last week.

“I think this group is all in together,” Ryan said. “We worked hard last year. We just weren’t quite as effective but all our guys believe in each other. They’re playing hard. I think they believe in the coaches. All our coaches have equal input. They work their butts off and we’re trying to do everything assigned to us properly. I think we’re all really coming together.”