All season, the Spartans’ defense was torn apart by teams that throw the ball and Saturday’s 42-14 drubbing by Penn State was no different.

The MSU secondary was considered to be the strongest part of the defense coming into the season — mostly because of its depth and experience — but rarely lived up to the hype.

Maybe the biggest reason is because they weren’t correctly used.

With the Big Ten moving to a spread-dominated league, there is more speed on the field. Maybe not as much speed as in the SEC, but speed, nonetheless.

Yes, some of the blame goes to the players for blown coverages, but players often were put in bad positions — especially the linebackers.

We heard all season that the Spartans were going to run their base defense and players have to make plays. Yes, at times individual players made mistakes, but the linebackers were forced all season to cover receivers who just had too much speed.

It’s unfair to ask junior linebacker Eric Gordon and senior Brandon Denson to be constantly covering slot receivers on a week-to-week basis. That’s just too difficult for linebackers who are taught to play the run first.

“It’s very, very hard because, at the same time, you have to worry about the run too,” junior linebacker Greg Jones said. “You have to worry about the run and the pass, but as linebackers we’re going to play the run first and try to get to the pass second, so that’s every linebacker’s mentality to stop the run. It’s just hard, and that’s why you have good athletes out there to try to do that and it’s a team game.”

With his receivers having a speed advantage, Penn State quarterback Daryll Clark was able to hit slot receivers on out-routes all game. And when the safeties moved in to prevent that, Clark beat the Spartans over the top.

If the secondary was so deep and talented, why were only four out there on most plays this season? On third and long, why were linebackers forced to cover speed receivers instead of defensive backs whose primary role is to defend the pass?

I know it’s important to be able to stop the run in the Big Ten. But most teams in the conference don’t even run the ball that often anymore — only four Big Ten teams are in the top 40 nationally in rushing (Ohio State, Wisconsin, Michigan and Illinois).

For all the “three yards and a cloud of dust” that the Big Ten historically is known for, the league is transitioning out of that and defenses have to be able to defend the pass.

All the while, the Spartans’ coaching staff made few adjustments.

Yes, they went to a three-man rush on third and long, but there still were three linebackers in the game and opposing quarterbacks were able to sit back with plenty of time.

In the last three seasons, the Spartans’ defense has allowed more yards per game each season — 345.5 in 2007, 355.8 in 2008 and 364.3 this season.

This trend is going to have to change if the Spartans care to become one of the Big Ten’s upper-echelon programs.

Chris Vannini is a State News football reporter. He can be reached at vanninic@msu.edu.