Most indispensable player: Iowa State

We're moving on in our series pegging the single player each team in the Big 12 can't afford to lose. He's also the player who will be most responsible for the team's ultimate success.

Next up: The Iowa State Cyclones.

Find more indispensable players here.

Most indispensable player(s): Linebackers A.J. Klein and Jake Knott

2011 stats: Klein and Knott combined for 231 tackles, 11.5 tackles for loss, three interceptions, three forced fumbles and two sacks.

Why Iowa State can't afford to lose them: This one's pretty simple. Klein and Knott are the most talented players on Iowa State's entire roster, and it's tough to imagine where the defense would be without them. They're arguably the No. 1 and No. 2 linebackers in the entire Big 12, and they happen to be on the same team. Neither is a physical marvel, but they're both tough and among the surest tacklers in the league.

Klein earned a share of the Big 12 Defensive Player of the Year honors last season. Knott played through injuries, but maintained a solid level of production. They showed a lot of promise as freshmen, and emerged as stars through their sophomore and junior years. Now, as seniors, it's time to try and help Iowa State climb back into a bowl game like it has done for two of the past three years.

One other huge reason this duo can't be replaced? Iowa State's defensive line has left a lot to be desired the past two seasons. Klein and Knott don't rack up many tackles for loss, but they do a nice job keeping 2-4 yard gains little more than 2-4 yard gains. Put average linebackers in there, and those gains are going to be a lot bigger, something closer to 6-10 yards. That doesn't happen very often in Ames. Klein and Knott are the reason why.