(Eds: Updates.) By LUKE MEREDITH AP Sports Writer 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.
''Improved, in a single word,'' Iowa State coach Paul Rhoads said when asked to assess his defense. ''You just don't know where you're at until you start lining up against other folks.''
That might not be apparent for weeks.
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.
Senior nose guard Jake McDonough is the only returning starter on the line and one of three seniors projected to start against the Golden Hurricane (8-5).
Roosevelt Maggitt, who is small for an end at 244 pounds, will start on the right edge after missing all but one game because of a knee injury a year ago. Senior Cleyon Laing will play inside next to McDonough, with junior Willie Scott entering his first season as a starter at left end.
Iowa State's defense has routinely been a soft spot for the Cyclones against the likes of Texas and Oklahoma and other Big 12 teams. Though the line is a bit uncertain heading into September, the Cyclones will at least have a veteran presence and some intriguing underclassmen in sophomore ends David Irving and Corey Morrissey and sophomore tackle Brandon Jensen.
Rhoads said Monday that Iowa State could play as many as a dozen defensive linemen this season.
''These guys are all practicing their tails off, and you practice with the idea that you're going to get in the game and help your football team win. So if you can roll guys out, you're affecting your preparation, you're affecting your morale,'' Rhoads said. ''But we think all of these guys can be productive.''
Cornerback Jeremy Reeves joins junior safety Jacques Washington as the returning starters in a secondary that lost star cornerback Leonard Johnson.
Senior Durrell Givins made three starts in 2011 and will get a shot at making at least 12 more at strong safety this season. The Cyclones will give junior Jansen Watson the first crack at right cornerback, with the likes of freshmen Kenneth Lynn and Sam Richardson ready to play in nickel packages and possibly start in the near future.
Junior Deon Broomfield is listed as the starting strong side linebacker alongside Knott and Klein. But at 6-foot and just 196 pounds, Broomfield is more of a fifth defensive back set to counter all the passing the Cyclones will see in the Big 12.
''I do know this for a fact. We're a smarter defense. We've coached things a lot less as we've gone through this training camp than we have in the past,'' Rhoads said.
Much of that has to do with the presence of Knott and Klein, both seniors and serious candidates for All-America honors.
''Just in case you might make a mistake or something, you know you're got those two guys backing you up,'' Broomfield said.