ATHENS — All those questions about Georgia’s defense? It won’t take long to get some answers.

The No. 13 Bulldogs open the season Saturday against ninth-ranked Oklahoma State, which returns most of the big guns from a group that averaged more than 240 yards per game a year ago — both running and passing.

“A lot of people talk about balance,” Georgia coach Mark Richt said. “Well, that’s about as close as you can get to being perfectly balanced.”

The Cowboys have a senior quarterback, Zac Robinson, who passed for 3,064 yards and rushed for another 562. They have a running back, Kendall Hunter, who piled up 1,555 yards and 16 touchdowns. They have a receiver, Dez Bryant, who had 87 catches for 1,480 yards and 19 TDs.

Wow.

“We all know they have a great wide receiver corps,” said linebacker Rennie Curran, one of the leaders of Georgia’s defense. “At the same time, they like to run the ball, they like to pound it.”

The Bulldogs were No. 1 as they prepared for their first game a year ago, but they didn’t come close to fulfilling that lofty ranking — largely because of a defense that was ripped to shreds by quality teams.

The first inkling of trouble came in the opener, when lower-level Georgia Southern managed to put up 21 points between the hedges. But things really fell apart against Alabama, which raced to a 31-0 halftime lead in Athens on the way to a 41-30 upset.

By the time the year was done, Georgia has surrendered at least 38 points five times. Two of those performances were particularly galling: a 49-10 rout by eventual national champion Florida, and a 45-42 loss to rival Georgia Tech, which overcame a 28-12 halftime deficit by scoring 26 straight points in the third quarter.

“We need to have a bit of redemption,” Curran said. “We feel like we’re on a mission.”

If nothing else, the Bulldogs have plenty of experience on defense. There are six returning starters along with senior tackle Jeff Owens, who has recovered from a knee injury that forced him to sit out all of 2008. The biggest loss was cornerback Asher Allen, who gave up his final season to enter the NFL draft.

“I feel like we’ve grown immensely,” Curran said. “Without a doubt, we all trust each other. We all know how hard each of us has worked individually. We’re just ready to get on the field. I can look to my left and look to my right and feel comfortable knowing that this guy is going to do what he’s supposed to do.”

But much of the attention will be directed at someone off the field.

Defensive coordinator Willie Martinez has come under increasing criticism from the fan base since taking over his duties in 2005, and it’s likely that even Richt’s strong support will wane if things don’t improve.

The numbers are troubling: The Bulldogs have surrendered an increasing number of points each year of Martinez’s tenure, the average rising from 16.4 a game his first season to 24.3 a year ago. Also, they’ve been burned for at least 30 points 11 times — something that happened only once in four years under his predecessor, Brian VanGorder.

The fact that VanGorder is right down the road, now serving as defensive coordinator for the NFL’s Atlanta Falcons, keeps his accomplishments fresh in the minds of Georgia fans. Some wonder if Martinez is cut out to make the sort of adjustments that are needed during a game, especially when a team such as Georgia Tech kept burning the Bulldogs repeatedly with its triple-option offense.

The biggest shortcoming last season was a lack of pressure from the defensive ends, who totaled just 9.5 sacks. The Bulldogs are counting heavily on an improved performance this year from new starters Roderick Battle and Demarcus Dobbs — especially in this first game.

“It’s very important to have pressure on Robinson,” Richt said. “We’ve got to find a way to contain him.”

Robinson is counting on a better showing from the Bulldogs than what he’s seen on film.

“They’re a great defense. They’re fast at every position,” he said. “We know with the season they had last year, it probably wasn’t up to par for their standard as a defense. We know they’re going to come out with a lot of extra motivation and be ready to go.”