Nebraska coach Scott Frost continued the back-and-forth debate between Alabama and his former employer, UCF, this week when he told an Omaha news station that not all of the Crimson Tide's 17 claimed national championships are legit.

"Alabama probably has one or two national championships they claim that weren't necessarily recognized by everybody," Frost told KETV.

Former UCF coach Scott Frost, who is now at Nebraska, said Alabama "probably has one or two national championships they claim that weren't necessarily recognized by everybody." Kevin C. Cox/Getty Images

Frost, who led UCF to a 13-0 season before taking the Nebraska job, said he thinks his former school's claim of a national championship is smart in terms of keeping the Group of 5 program in the national conversation. But he has also recognized that the true champion comes as a result of the College Football Playoff, which the Knights were kept out of despite an undefeated record.

Nonetheless, UCF players received championship rings and the program unveiled a championship banner during its spring game last month.

Alabama coach Nick Saban told USA Today this week that UCF has the prerogative to make the claim but "self-proclaimed is not the same as actually earning it."

"We've only had one undefeated team, and that is really hard to do," Saban said. "So I have a tremendous amount of respect for their team and what they were able to accomplish. ... And they can make every claim that they should have been in the playoff. I get that.

"But we have a system, and it's not fair to the people who went through the system and earned their way playing really, really good teams -- I mean really good teams -- and really tough games. It's not quite fair to them for somebody else just to decide to [claim a national championship]."

By beating Georgia in the national championship, Alabama boosted its number of claimed national championships to 17. Many of the early titles, however, were before the modern polling systems existed, opening them up to debate.