Did you hear that sound?

You know, that triumphant celebration that usually ensues when the mean substitute teacher leaves the classroom?

That was the sound you should’ve heard from Lincoln on Thursday afternoon when Nebraska announced that it fired athletics director Shawn Eichorst, who was about as well-liked as the state of Iowa among Husker fans.

Eichorst was fired for not reaching “high enough levels of competition,” which surely had nothing to do with the fact that a MAC school just waltzed into Memorial Stadium and dropped the mic on the storied Huskers. It was the last straw for Eichorst, who has made odd decision after odd decision, most notably the one to hire Mike Riley in the first place.

And while Eichorst was the one who opened the door for Riley, he was also the one who left it open for him to leave.

Credit: Bruce Thorson-USA TODAY Sports

The news of Eichorst’s departure isn’t entirely a death sentence for Riley, though it seems like a matter of time at this point.

After all, new athletic directors like to bring in their own guy. Why would anyone want their performance based on the job Eichorst did? That would be like letting a 5-year-old do your taxes. It would be silly, and it would only lead to trouble.

So what’s the immediate impact for Riley?

Well, lose to Rutgers and that Eichorst will be able to save him a spot on the plane ride out of Lincoln.

Riley might not even be safe if he loses to Illinois. Three losses this early in the season would mean the Huskers would end with no more than the nine regular season wins they had last year. That would only happen, of course, if they won out.

RELATED: What would actually get Mike Riley fired at Nebraska?

With the new early signing period, Riley’s only hope might be to win every game the rest of the season and prevent Nebraska from firing a coach in the midst of a hot streak.

Simple enough, right?

Then again, it’s a new athletic director. Whoever takes that job might have already made the decision to fire Riley before he even steps on campus.

And for anyone wondering if Nebraska will wait on a new coach because of Riley’s buyout, which states that he’ll be paid the remainder of the money left on his deal (he’s owed $9 million through 2020), that seems unlikely. They’ll fire a coach before they let their 55-year sellout streak die.

Can you blame them?

Credit: Bruce Thorson-USA TODAY Sports

Nebraska basically fired Bo Pelini because he wasn’t Tom Osborne. Three years in, Riley is barely Bill Callahan. But at least Callahan never lost to a MAC school at home like Riley did on Saturday.

At this point, it seems highly unlikely that Riley will get four years like Callahan did. Would things have been different had Riley not gone 6-7 in his first season? Absolutely. But that’s reality.

Now, reality is that Riley is sitting at 1-2 in Year 3 and without his most important advocate around to fight for him.

The question now is who will get to make the next big decision. Will Nebraska do what Minnesota did and let an interim AD hire its next coach? Well, it might not have worked out for Tracy Claeys in the Twin Cities, but Michigan did the same thing and wound up with Jim Harbaugh.

And how much will public perception dictate Nebraska’s next hire? Lord knows that’s what got Eichorst canned. There have been calls for Scott Frost to take over since the day Pelini was fired. Could Nebraska pass on him twice?

All of these things will play themselves out. It seems as if Riley’s chance to prove he could handle a big-time program already came and went. He’s been around long enough to know that a coach’s days are numbered when the guy who hired him is fired.

It no longer feels like a matter of “if,” but rather “when.”

Riley can’t like the sound of that.