Oklahoma football: Corey Nelson's confidence soars now that linebackers are again relevant in OU's defense

So far, so good. Through four spring practices, two rebirths are taking place: linebackers' relevance in Oklahoma's defense, and Nelson's self-confidence.

“Last year, I got down on myself,” Nelson said after Thursday's practice. “I got it back. I got my swag back ... but I was down in confidence once upon a time.”

Nelson's emotional dip came as Oklahoma coaches experimented with no-linebacker schemes late in the 2012 season, when the Sooners met some of the nation's most prolific spread offenses.

Opponents gashed Oklahoma's defense and, as a result, its linebackers' confidence while they stood idly on the sideline.

“Toward the end, we started to get a little relaxed and tended to not care,” Nelson said. “But after (coaches) saw that, they knew they had to make some changes and they had to fix it.”

Linebacker Tom Wort opted to skip his senior season at Oklahoma and enter the NFL Draft, a move that surprised almost everyone, including Nelson.

“He told me he was gonna leave after the last game, the bowl game,” Nelson said. “But I kinda didn't believe him. It threw me for a loop when he did, though.”

At Wednesday's Oklahoma Pro Day, Wort said schematic changes and frustration “somewhat” factored into his decision to leave.