The assumption is logical: So many contributors were lost from last year’s Kansas University football defense that, naturally, the 2006 version is going to take a big step back with inexperienced players roaming around.

It makes sense, but is it fair? Yes and no, according to coach Mark Mangino.

“I don’t think you immediately plug in young kids where you have veteran players and play as well right off the bat,” Mangino said. “What we do expect them to do is play smart football and good fundamental football.”

Only then, Mangino said, would the losses be easier to overcome.

KU’s defense is undergoing perhaps its most crucial period of the Mangino era, as spring drills continue through mid-April. Though Mangino said he thought the defense had loads of potential, there’s something to be said about leadership and experience and grit. Former Jayhawks Nick Reid, Charlton Keith, Charles Gordon, Kevin Kane and others had that.

This new crop, with only three returning starters and a lot of young faces, needs to acquire it.

“I’m the only returning front-seven starter, so I see guys looking to me as a leader,” defensive tackle James McClinton said. “But, also, I need that support. Everybody’s got to lead on their own. We’re a pack.”

With spring drills about halfway done, Mangino said he was a bit surprised with how well the defense was coming together. But he stops himself before getting too complimentary. There’s still work to be done.

“I’m really pleased with the tempo,” Mangino said. “The difference right now is that we have to learn on the run with some young players. Even though their tempo is very good at times, they have to get in the right spots.”

It’s looking like the 2006 defense could have more athleticism than the ’05 version. That’s a big deal, considering the ’05 defense was among the most punishing in college football, ranking third out of 117 Division I-A teams against the run.

Mangino acknowledges a rise in athletic ability, and, seeing the prowess that players like Aqib Talib, Mike Rivera, Joe Mortensen and Rodney Allen showed at times last year, it’s difficult to disagree.

That gift can only take you so far, though, and because of that, this spring has turned into a crash course on getting every other phase up to snuff on KU’s defense.

“I say it’s going to get much better,” McClinton said. “We’re going to keep on improving. Guys are going to get the defense down, get the technique down, and we’re going to be good next year.”