Iowa State’s second season under Paul Rhoads will officially begin Saturday afternoon when the Cyclones take the field in the annual Gridiron Club Spring Game.

The game will feature an offense led by seniors at quarterback and running back as well as an experienced group on the offensive line. Meanwhile, the defense will try to replace six starters, including the three departed starters of the linebacking corps.

“We’re an inexperienced front seven and it has shown this spring on defense,” Rhoads said in his news conference Monday.

During the team’s last scrimmage, Rhoads said he saw the defense making stops and making plays on the offense in the open field. The coach also said the unit had begun to catch up with the progress the offense has made in year two of the new system.

However, the former defensive coordinator is still not greatly pleased with where the unit is at, especially in year two of the system.

“Having a defensive background, I still think I’m discouraged by that — I’d like to see the defense playing at the same level as the offense,” Rhoads said.

Although the unit hasn’t progressed at the same rate as the offense, Rhoads said the defense lagging behind wasn’t a surprise to him or any of the other coaches.

The defensive line is recovering from two injuries suffered either last season or at the tail end of the year, but Rashawn Parker (torn ACL) and Bailey Johnson (broken foot) are slowly returning to practice and will be playing at full speed once fall practice begins.

At linebacker the story is different.

The graduation of last year’s starters — Fred Garrin, Jesse Smith and Josh Raven — has left sophomores Jake Knott and A.J. Klein as well as senior Matt Tau’fo’ou as the projected starters. The game Saturday will give both fans and coaches a chance to see the new group play in the system at game speed and will act as a measuring stick for its progression through spring practice.

“They’re showing their youth and inexperience,” Rhoads said. “As a position group on the defensive side of the ball, it takes longer to figure it out and play fast than it does at any other spot.”

However, the defense does feature a group in the secondary that will return two starters — as well as two players that saw significant playing time last season — and is a group that is expected to carry the ISU defense in 2010.

Any worries the coaches have about the defense may be offset by the experience and depth on the offensive side of the ball.

Saturday, the unit will showcase six seniors, including quarterback Austen Arnaud and the Big 12’s second-leading rusher Alexander Robinson.

“Offensively we have been productive throughout the spring,” Rhoads said. “The offensive line has been consistent and Austen Arnaud has been playing much better.”

The quarterback’s play was a hot-button topic during Rhoads’ Monday morning news conference, but the main storyline Saturday will still be the comparison between both the offensive and defensive progression.

“It depends on what the defense does this last week of practice to accomplish that,” Rhoads said. “If they don’t play like they did Saturday, then it maybe has a chance to be one-sided.”

While fans will get a look at the new faces on the defense and the older faces of the offense, they shouldn’t expect to see more of offensive coordinator Tom Herman’s spread offense.

It was often hinted last season that the playbook was gradually opened up as the season progressed, but Rhoads said offensive plans haven’t changed.

“It’s about doing the same things better and then tweaking the things we saw in the offseason that we think we need to improve on or we needed to add,” Rhoads said. “It’s not like Tom had a year one plan and a year two plan with the playbook installation. We attacked the playbook. The playbook is bigger than it needs to be anyway, offensively.”

The coach continued by saying that the staff has tweaked the scheme by adding to the plans for the running game because he believes they’ve got a “number of guys that are weapons” in the backfield and will allow them to keep their opponents off guard.

Rhoads had not yet decided Monday if the game would be the first-team offense and defense against the second units, but said there would be some players platooning for both the ones and twos.

There will be some Cyclones not in uniform Saturday. Offensive lineman Brayden Burris tore his MCL earlier in the spring and will be out for the next four weeks. Rhoads was confident Burris will be back to full speed upon recovery. Sophomore receiver Josh Lenz has missed most of spring with a shoulder injury suffered from a hit in practice, but may see game time as his recovery has gone smoothly.