Referee Bill Leavy, maybe best remembered for his admission of making major mistakes at a critical juncture of Super Bowl XL, will have a new role in 2015 as a supervisor within the league's officiating department. He'll be replaced as a referee by John Hussey, a former line judge, the NFL announced Friday.

Bill Leavy will no longer serve as an on-field referee as he is moving to a supervisory role in the NFL's officiating department. AP Photo/David Richard

As part of the announcement, the league also said that line judge Sarah Thomas, the first permanent female official in league history, has been assigned to referee Pete Morelli's crew.

Hussey is one of four new referees named in the past two years amid a significant shake-up of NFL officials. In total, the NFL has added 23 new officials over that time period and subtracted 20 via retirement, promotion or non-renewal, based on an unofficial accounting. In 2015, for the first time, the league will have three "swing" officials to help fill in for scheduling conflicts or performance issues.

NFL officials rarely draw attention for good calls, and Leavy is perhaps best known for admitting he "kicked" two decisions in the fourth quarter of Super Bowl XL, a 21-10 Pittsburgh Steelers victory over the Seattle Seahawks. Leavy didn't specify the calls, but speculation has centered around a holding call on Seahawks offensive lineman Sean Locklear and later a low block penalty on Seahawks quarterback Matt Hasselbeck.

The Seahawks trailed by four points at the time and would have had the ball at the Steelers' 1-yard line following a completed pass, but the call against Locklear nullified the gain. Hasselbeck would throw an interception on the next play.

Levy waited four years after that Super Bowl to acknowledge his impact on the game.

"It was a tough thing for me. I kicked two calls in the fourth quarter and I impacted the game and as an official, you never want to do that," he was quoted as saying in 2010. "It left me with a lot of sleepless nights. I think about it constantly. I'll go to my grave wishing that I'd been better.

"I know that I did my best at that time, but it wasn't good enough."

In 2013, the NFL downgraded Leavy for mistakes his crew made in an early September game between the Green Bay Packers and San Francisco 49ers.