STATE COLLEGE, Pa. -- Longtime linebackers coach Ron Vanderlinden and quarterbacks coach Charlie Fisher are no longer with the Penn State football program, according to the school.
The university's official statement said both coaches "have resigned to pursue other opportunities." It wasn't immediately clear what those other opportunities were.
Neither Fisher nor Vanderlinden returned calls from ESPN.com seeking comment.
"I've greatly enjoyed my 13 years at Penn State and all the student-athletes I had an opportunity to work with," Vanderlinden said in a news release. "I wish Coach [Bill] O'Brien and Penn State nothing but the best in the future."
O'Brien will begin a job search immediately and said he will not comment until the positions are filled. Potential candidates are not yet known.
The assistants' departures come just three days after the Nittany Lions clinched their second winning season during unprecedented sanctions. Penn State upset then-No. 15 Wisconsin on Saturday, the first time PSU defeated a top-15 team on the road since 2008, to finish the season at 7-5.
Vanderlinden's departure was considered especially surprising, given his track record. He's been a part of the staff since 2001 and oversaw a program widely known as Linebacker U. He coached several All-Americans such as Michael Mauti, Dan Connor and Paul Posluszny -- in addition to NFL stars NaVorro Bowman and Sean Lee.
He also played an important role in the commitments of at least a half-dozen pledges for the 2014 class, including four-star linebacker Troy Reeder (Wilmington, Del./Salesianum).
"At this point it does not affect my decision," Reeder said earlier in the afternoon. "Coach [Bill] O'Brien and [John] Butler will be coming down to see me today and are going to explain everything in more detail."
Vanderlinden has coached since 1978 and served as Northwestern's defensive coordinator from 1992 to 1996 -- coaching current Wildcats coach Pat Fitzgerald -- and then coached at Maryland from 1997 to 2000 before landing in Happy Valley.
Fisher was one of O'Brien's first hires at Penn State and helped spring former walk-on Matt McGloin to a school-record 3,266 passing yards in 2012. Fisher arrived at the school after spending one season at Miami (Ohio), where he acted as the quarterbacks coach/passing game coordinator. Before that, he was an assistant at Vanderbilt for nine seasons.
"I want to thank Penn State and Coach O’Brien for the opportunity to be a part of the program the past two seasons,” Fisher said in the news release. “It was a great experience and I am very proud of what we accomplished. Now I'm looking forward to the next chapter and making a positive impact on the next group of players I have the privilege of working with."
Tom VanHaaren contributed to this report