Oklahoma defensive line coach Jerry Montgomery, one of the Sooners' top assistants, is headed to the NFL, the school announced Tuesday.

"This is a rare opportunity for Jerry and his family to join one of the finest organizations in the National Football League," coach Bob Stoops said in a statement. "I appreciate the positive impact that Jerry has made with our defensive line the past two seasons, as well as his many other contributions to Oklahoma Football.

Jerry Montgomery is moving on from Oklahoma to join the Packers' coaching staff, sources say. Jackson Laizure/Getty Images

"The NFL is getting a fine man and a very talented football coach. I support Jerry's decision to further his career goals working with one of the most stable and successful franchises in pro football."

Oklahoma's announcement did not reveal which NFL team lured Montgomery away, but he was officially named to the Green Bay Packers' staff Thursday as a defensive front assistant.

The Sooners hired Montgomery away from Michigan two years ago, and he quickly turned the Oklahoma defensive line into one of the Big 12's best during the 2013 season. The Sooners finished the year by overwhelming Alabama in the Allstate Sugar Bowl, sacking quarterback AJ McCarron seven times in a victory over the Crimson Tide.

Montgomery also gained acclaim as a tenacious recruiter. Last week, the Sooners signed a trio of defensive linemen ranked in the ESPN 300.

Underscoring Montgomery's value, on the same day last month when Stoops announced he'd fired co-offensive coordinators Josh Heupel and Jay Norvell after a disappointing 8-5 season, he also revealed he had promoted Montgomery to co-defensive coordinator.

"My family will be forever grateful to Coach Stoops for providing me with the privilege of learning from him and the rest of his staff at the University of Oklahoma," Montgomery said in a statement. "The past two years have been invaluable helping me grow personally and professionally. It's truly been an honor to coach such a wonderful group of student-athletes at OU, and I'll continue to follow their progress closely."

Montgomery's departure means Oklahoma will have four new assistants on its staff next season. Only offensive line coach Bill Bedenbaugh and linebackers coach Tim Kish will be coaching the same positions they did last season.

"The University of Oklahoma continues to be an attractive destination for some of the nation's elite coaches and players," Stoops said. "I have already begun the search process to bring another talented defensive line coach into our program."