It’s worthwhile taking one last look at the gray areas of the 2007 Kansas University football team, unit-by-unit, on paper before the the Jayhawks take the field tonight at Memorial Stadium in the season opener against Central Michigan.

Special teams: KU coach Mark Mangino believes in using his best players here, and that’s why the Jayhawks’ special teams usually fare well. Even so, Kansas lacks an experienced punt returner, and that’s a difficult job. Tracking a punt in the air well enough to field it cleanly while deciding whether to signal for a fair-catch or try to return the kick requires a sure-handed multi-tasker.

Offense: Whenever an offensive line has been together for a while, the blockers talk about how much their communication has improved and how that allows them to be so much more efficient. This line has three new starters, so it won’t be at its best right away. The line is younger, but bigger and probably healthier than the previous one. By the time the Big 12 season arrives, it should be as good as last season’s. By season’s end, it should be better.

Defense: Can the Jayhawks survive playing a freshman at cornerback better than they did when Anthony Webb manned the position a year ago? Chris Harris, a true freshman from Bixby, Okla., is on the short side, but he can fly and plays with confidence, such a vital trait for the position. Kendrick Harper’s injury opened the spot for Harris.

“He’s been impressive,” Mangino said of Harris. “He plays with great enthusiasm. He has great alertness. He’s alert. He runs really well. He’s competitive. He doesn’t back down from anybody.”

Yet, he was matched up against high school receivers just last fall. He could get schooled at the outset.

Safety play should be stronger than a year ago, which will help Harris. A strong pass rush would help him even more. Can KU come closer to 2005’s terrific pass rush than 2007’s soft one? Too many unknowns to answer that.

“We don’t know what guys are going to do until they play in the game,” Mangino said of players sometimes seemingly coming out of nowhere. “You can do all the scrimmage work you want, your practices can be as physical as you want them to be. We do all those things, but there’s no substitute for playing against an opponent on any position on the field.”

Jeff Wheeler and Maxwell Onyegbule, listed for the moment as second-team on the depth chart, could surprise. Outside linebackers James Holt and Mike Rivera also could help the secondary by harassing the quarterback.

College football players, still growing physically, mentally and emotionally, can improve so much from one season to the next and can make names for themselves so quickly, as did KU’s Aqib Talib and Kansas State defensive end Ian Campbell.

Who could be this season’s players who come seemingly out of nowhere?

“The guys who were in nowhere, we don’t know which ones are going to do that,” Mangino said.

“Hopefully, there will be a lot of them. I will tell you this: Each year we’ve been here, our recruiting has improved each year, but this past year’s recruiting class is leaps and bounds better than any recruiting class we’ve brought in here.”