Updated

Alabama spent two months barely seeming to miss all those defensive stars now in the NFL.

The fourth-ranked Crimson Tide has certainly felt their absence the past two weeks when it became evident this defense doesn't quite measure up to the lofty standards set by the 2009 and 2011 national championship groups.

The still-formidable defense has had uncharacteristic missed tackles and struggles getting the opposing offense off the field on third downs against No. 8 LSU and No. 9 Texas A&M. No game-changing pass rusher like linebacker Courtney Upshaw has emerged, either.

Alabama (9-1), which hosts Western Carolina (1-9) on Saturday, was leading the nation in every major defensive category just like last year's group before showing more vulnerability against the Tigers and Aggies. Those teams both managed more yards and points than any other offense had against the Tide this season.

"The last two weeks, lots of issues not getting off the field on third down, which hasn't been a real factor all year long," Alabama coach Nick Saban said. "But in the last two weeks, we gave up 14 points in the second half at LSU, going 0-for-7 on third downs during that time and we started this (Texas A&M) game 0-for-7 on third down and got behind in the game because of it. When you create those situations you've got to get off the field.

"It's not just the pass rush. It's also the discipline of everybody doing what they're supposed to do in rush as well as coverage."

In those two games, the defense has given up 853 yards, a 55-percent conversion rate on third downs — more than double the success rate going into those games — and scores on all but one of the opponents' seven trips inside Alabama's 20-yard line.

Only Georgia Southern's option attack managed to produce 300 yards against Alabama in 2011.

Most teams would still love to have Alabama's defensive issues this season, especially after losing three NFL first-round picks: safety Mark Barron, cornerback Dre Kirkpatrick and linebacker Dont'a Hightower. Plus, Upshaw was taken early in the second while noseguard Josh Chapman and cornerback DeQuan Menzie were also drafted.

Alabama still leads the nation in scoring defense and is second in total yards allowed. Plus, cornerback Dee Milliner and linebacker C.J. Mosley are both semifinalists for the Chuck Bednarik Award given to the nation's top defensive player.

However, 13 SEC players have more sacks than the four produced by team leaders C.J. Mosley and Adrian Hubbard.

"I don't think we have a dominant rusher like we had a year ago," Saban said. "I think we have guys that as a unit and as a group can be effective."

Texas A&M's 29 points was the most allowed by the Tide since a 35-21 midseason loss to South Carolina in 2010.

Of course, Alabama faces few such fast-paced offenses or dual-threat quarterbacks like the Aggies' Johnny Manziel.

Saban said the Tide couldn't get lined up eight times when Texas A&M snapped quickly.

"That's just not good," he said. "It's not good coaching. It's not good for the players to have a chance to be successful and execute. That's something that we need to work on more in the offseason and do a better job of."

Lester said he can't remember a two-game stretch where Alabama had so many missed tackles, some of them attributable to the slippery Manziel.

Saban said that has become a concern.

"We've had more missed tackles, we've had more yards after catch, after first contact or first missed tackle, especially on space plays," he said.

"That's one thing we've always been is a good tackling team and a good tackling secondary. That is something that we need to improve on."