Expectations help define success in almost any endeavor. Whether it’s business or personal, you have to believe something can be achieved before it can happen.

Oklahoma entered this season having to replace 10 starters taken in the 2005 NFL draft. So many departures left the Sooners an uphill climb just to stand still in college football’s pecking order.

Still, there were no pleas for patience from OU’s camp. The program entered spring practice with the belief that players come and players go. Such is the circle of life in the college game.

But after beginning the season 1-2, even OU coach Bob Stoops is now admitting the expectation level for his team may have been too high.

Though there was no warning siren blaring, but Stoops now says he knew it would not be easy. The reason was simple: OU would be counting on inexperienced players to do what seasoned veterans had done the year before.

“I can’t say that there were signs,” he said. “We understood what we had lost. Here, you’re going to sit here and act like I’m making excuses. We don’t do that. But in the end, there’s a lot of guys that are gone.”

And replacing them has been a lot harder than any expected. OU went from a quarterback that had won a Heisman Trophy and played in two national championship games (Jason White), to Rhett Bomar, who will make his third career start when OU hosts Kansas State at 6 p.m. Saturday.

The offensive line is trying to replace a core group that had started almost every game the previous three seasons. The current group has been shuffled in all three games and is still reeling from two tackles — Akim Millington and Brandon Keith — quitting the team and two freshmen — Branndon Braxton and George “Duke” Robinson — being counted on to replace them.

As far as the receivers go, OU had to replace three — Mark Clayton, Mark Bradley and Brandon Jones — taken in the first three rounds of the NFL draft.

Defensively, OU entered the season having to break in a new secondary and relatively new defensive line. Getting tackle Dusty Dvoracek back helped, but the three top defensive ends coming into the season — Larry Birdine, John Williams and Alonzo Dotson — are all out. Birdine and Williams have lost their season to injury and Dotson was ruled academically ineligible.

Still, Stoops wouldn’t buy into the notion the Sooners couldn’t remain at the same lofty perch they’ve occupied since 2000. To him, that would mean admitting defeat.

“For me to sit there and say that in the spring, it gives my team an excuse not to do well,” he said.

But the excuse is now the reality.

The Sooners have looked every bit the inexperienced team they appear to be on paper. They’ve been plagued by turnovers and mental mistakes, both distinguishing traits of a team forced to rebuild rather than reload.

“It’s pretty obvious some of the inexperience has plagued us,” Stoops said. “Just in taking care of the football, we went five straight games last year without a turnover. That’s because there were a lot of guys handling the ball that were used to handling it and had experience handling it. Right now that’s not the case.