Oklahoma coach Bob Stoops has some scary words for the rest of the Big 12.

When asked about his defense this spring, the Sooners’ veteran coach left no doubt he was pleased about the progress of that unit.

Eric Striker is working at outside linebacker and nickelback this fall for the Sooners. Kevin C. Cox/Getty Images

“We’re light years ahead of a year ago,” he said.

A year ago the OU defense was in flux. It was obvious that changes were needed, but the search for an identity continued throughout the spring of 2013. OU eventually settled into a switch from a 4-3 base defense to a 3-4 look, and finished atop the conference in fewest yards allowed (350.2) and fewest passing yards allowed (212.6).

This season, defensive coordinator Mike Stoops and the rest of OU’s defensive staff are using the spring to expand and improve their defensive system, tinkering to find the best way to deploy an athletic and young group of defenders.

“A year ago we weren’t in systems yet,” Bob Stoops said. “Now we’re not only in it, we’re expanding it and polishing it out. We’re giving these guys some roles of dropping and rushing. I’m starting to feel, with Mike and the defensive coaches, we’re getting our guys in the best spots, and I think it will really help us.”

Linebacker Eric Striker, a coaches' second-team All-Big 12 selection, has spent time working on his pass coverage skills at the nickelback position after finishing his sophomore season with 10.5 tackles for loss, including 6.5 sacks. The ultimate goal is to put Striker in the best position to make plays as a junior while also developing his versatility as a defender.

“On normal yardage [downs] we probably rushed Julian (Wilson) twice as much as we did Eric,” Bob Stoops said. “We get in third down and Eric always rushed. First and second downs, it can be a little bit reversed. That’s all we’re saying, giving him more opportunities to do what he does best.”

Even with the success the OU defense had in 2013 as the foundation of a 11-2 season, Mike Stoops looks back on last season as a learning experience. Last spring was about finding a system and an identity. This spring is about expanding and improving the current system.

“I think you learn a lot and you can add,” Mike Stoops said. “We are so good at some things now that we can continue to tinker with different calls in how we want to do it. We continue to expand in little ways. We are not going to change a whole bunch. I think we will add more to our package as we go along.”