AMES, Iowa (AP) - Iowa State knows it can rely on Jake Knott and A.J. Klein, one of the best linebacking tandems in the nation.

It's the other nine defensive starters who will determine just how far the Cyclones go in 2012.

Iowa State has plenty of depth on a defense that got better as last season wore on. But where all those pieces fit around Knott and Klein - first-team All-Big 12 picks who combined for 231 tackles in 2011 - needs to be sorted out with the Cyclones set to open the season Saturday against Tulsa.

Iowa State (6-7 in 2011) is replacing six starters from a defense that allowed 29.4 points a game last season. Though there are some familiar names in line for starting jobs, the Cyclones will be asking many of them to contribute more than they ever have.