Patrick Peterson was a big loss for LSU’s defense.

So was losing All-American Drake Nevis at defensive tackle.

The most critical loss for LSU’s entire team, however, may have been at middle linebacker. That’s where Kelvin Sheppard used to pound the beat, keeping law and order as the linchpin and emotional leader of LSU’s defense.

It’s perhaps not surprising then that two players are vying to be his replacement.

Both admittedly have their plusses and minuses.

There is Karnell Hatcher (6-foot-2, 212 pounds), a senior from Delray Beach, Fla., who has wisdom and guile on his side. What he doesn’t have is experience at linebacker, having downshifted from free safety where he started LSU’s last 11 games in 2010.

Then there is Kevin Minter (6-1, 225), a redshirt sophomore from Suwanee, Ga., who has three years as a linebacker in his corner but little practical experience. He played in 11 games in 2010, all in reserve duty, with 15 total tackles.

Both men look at their competition and see the qualities they wish they had.

“He has the experience of playing in the SEC,” Minter said of Hatcher. “That’s an edge for him. It’s a totally different world playing in a game against the big-time opponents we do.”

“Kevin has a bigger edge than me,” is Hatcher’s reply. “He’s been there three years, knows where the gaps are when where the linemen are. I’m still learning. I feel he has a bigger edge.”

Right now the duel between them is like a hotly contested political contest - too close to call. LSU coach Les Miles said both played about even in Saturday’s first fall scrimmage.

For them, there is no easing into the role, like someone sliding gently into a hot tub. The regular season begins Sept. 3 with a trial by fire against one of the nation’s very best offensive teams: the Oregon Ducks.

Hatcher and/or Minter will be responsible for making the calls for LSU’s defensive front seven against an opponent that works perpetually in two-minute drill mode, an opponent that at times may give the Tigers just seven seconds between plays.

Learning on the fly never had more meaning, but Minter has no complaints.

“I’m excited for the game,” he said. “It’ll be a great test for me and the rest of the defense.”

Hatcher had 64 tackles last season and felt like he’d built a home in the LSU secondary where he’d live out the rest of his college days. But by late in 2010 he began to hear whispers that LSU’s coaches might want him to take on a new role in 2011 with Sheppard (now with the Buffalo Bills) headed to the NFL.

At first he admitted he wasn’t happy with the change.

“I was kind of down, but I’m all for the team so I was ready to help out,” Hatcher said.

“I feel I still have some learning to do, but I feel (linebacker) fits my game pretty well - physical and all that. But the difference is I have to think faster and play faster.”

Defensive coordinator John Chavis, who coaches LSU’s linebackers personally, isn’t ready to pin a starting label. But he does believe Hatcher will be one of the surprise weapons in the Tigers’ defensive arsenal in 2011.

“I think the one guy that’s going to really impact us the most at linebacker in terms of people not knowing him is Karnell Hatcher,” Chavis said.

“He’s still learning, but let me tell you he’s a football player and he’s got great instincts and can find the football. Having him inside is going to be a big plus for us, particularly with the number of spread teams we’re going to be facing.”

As for Minter, Chavis said: “Kevin Minter’s had a great spring and a great offseason, so certainly those two are going to be battling for the starting position inside.”

If it’s Hatcher, he’ll have a fan backing him up in Minter.

“Whatever fits,” Minter said. “If (Chavis) feels Karnell is ready, it’s whatever is great for the team.”

If the starter is Minter, he’ll have a fan behind him in Hatcher.

“I’m still going to root him on, still try to make him better,” Hatcher said. “We’re going to push each other to get better.”

Considering the kind of player LSU lost in Sheppard, two playing as one may be just what the Tigers need.

Blackwell back

LSU’s two-a-day practice sessions Monday were closed to the media, but reportedly starting right guard Will Blackwell was back at practice after missing several practices last week, including the Saturday scrimmage.

The reporter was Blackwell himself.

“Just a few bumps and bruises, taking precautions but I’ll be fine,” Blackwell said Monday. He said his time off had nothing to do with the severe leg injuries he suffered in last season’s opener against North Carolina.

A look ahead

With fall semester classes beginning next week, Monday marked the Tigers’ last scheduled two-a-day practice session.

The Tigers will practice once Tuesday and Wednesday in preparation for their next scrimmage, slated for Thursday afternoon in Tiger Stadium.