SOUTH BEND (AP) — At 212 pounds, Harrison Smith looks out of place at linebacker. He feels out of place, too.

That's because the Notre Dame sophomore doesn't see himself as a linebacker. Twenty pounds or more lighter than most of the other Irish linebackers, he sees himself as a safety who is just playing a little closer to the line than normal to help out the team.

"It's fun playing down in the box, but I feel more comfortable when I'm back," Smith said. "It's just what I'm used to."

That's because until midway through spring practice, the last time he had played linebacker was for a few plays back in middle school. The Irish coaches wanted to get more athletic at linebacker, so in spring they approached the former Tennessee high school decathlon champion about making the switch.

He was a little hesitant, but saw it as his quickest way to get on the field after not playing as a freshman.

"I didn't know what to think at first. But once I started getting in there, it wasn't really that big of a change," he said.

The biggest challenge has been reacting quicker to the action as well as taking on some much larger blockers. But the move has been a success. He's fifth on the Irish (6-4) in tackles with 42 and leads the team in tackles for loss with seven and is second in sacks with 2.5.

"He's one of our better defensive players. He's very, very disruptive," coach Charlie Weis said. "Obviously you can go against some teams now and he can become a bit undersized, because at 210, soaking wet, that's what he is. But he's played so aggressively, he's been like a strong safety down in the box all year."

The one change moving to linebacker that Smith has refused to make is to wear knee braces, which all the other Irish linebackers do to protect themselves from cut blocks.

"I feel like they slow me down," Smith said.

The other linebackers give him some good-natured kidding over it.

"We say, 'Oh, that guy must be a safety, kind of how he catches the ball, and he does some safety things,'" said linebacker Maurice Crum Jr., the defensive captain.

But Crum said the other linebackers and teammates all respect Smith.

"He works hard. He does whatever he's asked to do and he's just one of those guys that you love to have around. He's a great locker room guy and just one of those guys that you enjoy playing with and having him out there," Crum said.

The coaches have given Smith, who is from Knoxville, Tenn., the nickname of "Hayseed."

"It's just seen as that type of place where a hayseed would be from," said Smith, who has long hair that hangs over his eyes.

His teammates say he just has a laid-back personality until he steps on the field, when he suddenly becomes aggressive. Sometimes too aggressive.

Against Pittsburgh he was called for a late hit on a third-down play that kept alive a drive that led to a touchdown by the Panthers, who ended up winning in four overtimes. Smith called it a "stupid, selfish penalty."

Smith, though, has made plenty of big plays for the Irish. He's run the ball on two successful fake punts, running for 23 yards against Stanford and 35 yards against Washington. None of the Irish running backs have had runs that long this year. He had a team-high nine tackles against Boston College, including seven solo tackles.

Weis has already told Smith he expects him to return to free safety next season, filling the spot being vacated by the graduation of David Bruton.

"I told him, 'You're going to have to lose a little weight and get a haircut,'" Weis said.

Smith was happy to hear that, except for the part about the haircut.

"I'm pretty sure he was joking," Smith said. "At least I hope so."