SOUTH BEND, Ind. -- Derek Landri and Joe Brockington don't need your help. They can fill in the blanks on their own.
Like the other members of Notre Dame's defense, Landri and Brockington know exactly what the outside world -- media, fans, opponents -- thinks of them.
Here's a hint: It's not much.
"Everyone's talking that our defense is still the downfall of the team," said Landri, a senior defensive tackle who has seven sacks and 15 tackles for loss this season. "Apparently, there's a lot of people in the country that feel that we're not championship-caliber."
Every time Brockington hears Notre Dame's star-studded offense being praised, he knows a "but" is coming.
"They're like, 'Oh, your offense is good, but '" the senior linebacker said. "It's always our defense this, our defense that. It definitely bothers you."
Many of the preseason labels attached to the Notre Dame defense remain as it prepares for an image-defining showdown Saturday against No. 3 USC (ABC, 8 p.m. ET). Though the defense has better numbers than last season, the scouting report on the unit still reads something like this:
• Too slow
• Prone to breakdowns and overpursuit
• Vulnerable on the edges
"Whenever you hear somebody talking trash about you, all the analysts on TV, it definitely gets you going and makes you want to prove something out there," defensive tackle Trevor Laws said. "I've definitely heard it this year."
A portion of the criticism is unwarranted.
Comparing the numbers from 2005, the Fighting Irish have improved their national rankings in total defense (75th to 44th) and scoring defense (53rd to 47th). They average more sacks (2.64 per game) and more tackles for loss (6.55 per game).
Notre Dame also is ranked better in pass defense (39th vs. 103rd), but its pass defense efficiency rating of 132.7 is troubling.
"Yards per game and points per game, that's what you go by," coach Charlie Weis said. "They're giving up less yards and less points."
Sounds simple enough. So why all the doubt?
Perhaps because Notre Dame, just like last season, allows more than its share of big plays, even against weak teams.
Consider: Irish senior quarterback Brady Quinn has competed 11 passes for 35 yards or longer this season. Opposing quarterbacks have combined for exactly the same number.
"It's frustrating," senior cornerback Mike Richardson said. "We stress not giving up the big plays and then we still do. It's little things, maybe at the snap or not looking for the ball. Those little things, unfortunately, lead to bad things."
Among the wide receivers who burned the Irish this season are Georgia Tech's Calvin Johnson (7 receptions, 111 yards, 1 TD), Michigan's Mario Manningham (4 receptions, 137 yards, 3 TDs), Purdue's Selwyn Lymon (8 receptions, 238 yards, 2 TDs), UCLA's Marcus Everett (6 receptions, 102 yards, 1 TD) and North Carolina's Hakeem Nicks (6 receptions, 171 yards, 2 TDs).
"It starts with denying big plays," Notre Dame defensive backs coach Bill Lewis said. "People are going to get their completions. You want to deny the easy touchdown pass.
"As we mature in what we're doing, hopefully we can improve in that area."
Limiting big plays tops Notre Dame's priority list, but generating takeaways comes second. The Irish are tied for 102nd nationally in takeaways (15), collecting only seven in their last seven games.
Last year Notre Dame tied for 36th nationally in takeaways with 24.
"Coach Weis talks about this nasty team," defensive end Chris Frome said. "You expect a nasty team to create turnovers on the defensive side of the ball. We've been better with that the last couple weeks, but it's something we need to improve on.
"We need to create turnovers to win these big games."
Saturday's game certainly constitutes as big, with USC in line for a national championship spot and Notre Dame trying to cement a BCS invitation.
Put simply, a win validates Notre Dame's defense and underscores the progress that has gone largely unnoticed.
"We definitely have improved in various aspects," Abiamiri said.
Take Brockington, for example. After collecting just 12 tackles in two seasons, he entered the starting lineup Sept. 30 and solidified the third linebacker spot, averaging 6.9 tackles in the last seven games.
And no group on the team improved more than the defensive line, which stuck together after end Ronald Talley left the program Oct. 12. After collecting only eight sacks in the first five games, Notre Dame picked up 21 in the last six contests.
"They've always been a close-knit group," defensive line coach Jappy Oliver said. "They're just starting to reap some of the rewards of it now."
The wait for Victor Abiamiri to blossom into a premier pass-rusher ended. The senior end is tied for 10th nationally in sacks (.91 per game) and tied for 22nd in tackles for loss (1.32 per game).
Landri and Laws have solidified the middle, combining for 55 tackles (12 tackles for loss) in the last four games.
"It's funny because they play the same amount of plays because they're basically the same guys," Weis said. "Now the thing is they're in the backfield so much more. They're both very quick players, which gives them an opportunity to penetrate."
Notre Dame has allowed only one first-half offensive touchdown in the last three games, but its endurance will be critical against USC, which has outscored opponents 96-41 in the fourth quarter this season.
"People care about how you start, but it's always how you finish," Oliver said. "We haven't finished games like we've started. I'd like to think our best football's ahead of us. It needs to be because our best opponents are ahead of us."
Weis has no shortage of motivational tools this week -- his players entered Sunday meetings and had USC hymns "Fight On" and "Conquest" blaring in their ears -- but the defenders need no prodding.
"It's in games like this where you expect your defense to perform and you expect to earn a name for yourselves," Frome said. "We've been waiting for that statement game to really prove ourselves.
"It'd be nice to see it come out on Saturday."
Legacy has been the buzzword around campus as record holders such as Quinn and Jeff Samardzija wrap up their Notre Dame careers.
What will be the defense's legacy?
"This defense is either going to rise to the occasion and play, or it's not," Landri said. "Then the legacy's going to be written. It's up to us on how we want it to be written."
If things go well, Brockington already has the title.
"They proved the critics wrong."
Adam Rittenberg covers college football for the Arlington Heights (Ill.) Daily Herald.