Lincoln, Neb. ? Bill Callahan has five games to prove to Tom Osborne why he should remain Nebraska’s football coach.

That’s the bottom line after Steve Pederson, the man who hired Callahan in 2004, was fired and replaced this week by the Hall of Fame coach and leader of the Cornhuskers’ dynasty of the mid 1990s.

“I look at it as an opportunity,” Callahan said. “That’s just me. I’m optimistic.”

Callahan is 26-18, with last year’s run through a mediocre Big 12 North his greatest achievement.

The Huskers earned their highest ranking under Callahan at No. 14, after starting this season with two wins. But lopsided losses to Southern California, Missouri and Oklahoma State and a one-point win at home over Ball State have left the Huskers 4-3 and 104th nationally in defense entering Saturday’s home game with Texas A&M. Osborne’s initial assessment?

“We’d like to see the intensity level pick up to what we’re accustomed to,” he said.

Osborne said he’ll make a decision on Callahan after the season.

If Osborne chooses change, the next coach would be secure in knowing he’s “Osborne’s guy,” a title that should come with the tacit approval of Husker Nation.

Also, Osborne’s status might help draw more prominent candidates than the last coaching search did.

After Frank Solich was fired in 2003 by Pederson, potential candidates such as Florida coach Urban Meyer, then at Utah, avoided Nebraska. After all, if a coach can get fired after going 9-3 and 58-19 in six seasons, the margin for error must be razor thin.

If Callahan is let go, some of the potential candidates that have already been talked about include LSU defensive coordinator Bo Pelini, Buffalo coach Turner Gill and Wyoming coach Joe Glenn.

Pelini is on the short list of hot assistants in college football these days. He was hired by Solich as Nebraska’s defensive coordinator in 2003 and proved extremely popular. He was interim coach for the 17-3 Alamo Bowl win over Michigan State, and as he walked off the field Nebraska fans chanted “We want Bo.” Pederson interviewed Pelini, but Pelini said he never was given the impression he had a chance.

Gill is the former Nebraska quarterback of the early 1980s. Another popular figure in Huskers lore, he was a longtime assistant under Osborne and Solich and interviewed for the head coaching job in 2003. Callahan retained Gill as receivers coach, but Gill left after the 2004 season.

Glenn has built Wyoming into a Mountain West contender in his five seasons with the Cowboys. Glenn, who has won national titles at the Division I-AA and II levels, is a Lincoln native.

University chancellor Harvey Perlman has said the football program was in “disarray,” and the 70-year-old Osborne promises to stay as long as necessary to put the house in order.

“My intention is to work myself out of the job,” Osborne said. “I would hate to speculate on the number of months or years or whatever it may be.”

His first task is to get to know Callahan and the rest of the football staff.

With Osborne serving three terms in Congress (2001-07) and making a failed gubernatorial run last year, there has been little opportunity for interaction between him and Callahan.

Osborne said he met with Callahan for two hours when the coach was first hired, and they had a one-hour meeting last week during the reunion of the 1997 national championship team.

Callahan has never publicly embraced Osborne’s legacy. His charge when he was hired, he often says, was to “flip the culture” of the program.

Callahan, the former Oakland Raiders coach, brought an NFL mentality to the Huskers, not to mention the West Coast offense.

Under Bob Devaney and Osborne, the program was known for overachieving small-town kids playing for the ‘N’ on their helmets, not necessarily for the opportunity to go on to the pros. Even Osborne’s close-to-the-ground offense reflected the state’s agrarian roots.

Callahan dismissed the old guard, down to the football trainer.

But Osborne has been an inescapable presence for Callahan – now more than ever.

Osborne’s name is on the building where the football program is housed. In front of that building is a bronze statue of Osborne, who won national titles three of his last four years and retired with 255 wins in 25 seasons.

When asked recently whether this season’s struggles might give him a greater appreciation for the incredible 1990s’ run under Osborne, Callahan would not utter Osborne’s name.

Instead, he talked of his admiration for what Southern California has accomplished in recent years and added that he was impressed with all the coaches who put together dominant runs. Then he named Frank Leahy of Notre Dame in the 1940s and Bud Wilkinson of Oklahoma in the 1950s.

Osborne’s re-entry into the picture represents an opportunity for him, as well, to make amends.

In some quarters, Osborne is criticized for using his considerable clout to install Solich, his longtime lieutenant, as head coach in 1998 rather than let then-athletic director Bill Byrne make the hire.

Osborne also insisted Solich retain the assistant coaches.

Those assistants were aging and, in some cases, ailing. Solich did fine with the players recruited under Osborne’s watch, but slippage occurred as they graduated. After the Huskers went 7-7 in 2002, Solich fired most of his assistants and brought in a more dynamic staff of assistants – Pelini among them.

But lopsided losses to Missouri, Texas and Kansas State in 2003 sealed Solich’s fate, and Pederson made the controversial decision to fire him.