I haven't watched a lot of Clemson this year, but from what I gather offense was more of an issue than defense. I'd expect a low scoring game, and it appears Vegas agrees with the O/U at 45.5.
Our defensive line is very good, lead by Will McDonald who is a first team all-american. Our LB corps is also good; Mike Rose was the Big 12 defensive player of the year last year - was good this year as well, but battled some injuries. If there is a weakness in the defense, it is in the passing game as our secondary had some issues (particularly in the West Virginia and Texas Tech games). Our safeties are better against the run; Isheem Young hits as hard as I've seen a safety hit. I'm looking forward to it; should be a fun game!