South Carolina high school running back Matt Colburn made national news when he and his high school coach claimed his 2015 Louisville scholarship offer was pulled right before National Signing Day, after nearly a year of commitment.

In its place, Louisville offered Colburn a grayshirt. Colburn balked and signed with Wake Forest.

Louisville declined to comment on Colburn, grayshirting or any other process of roster building under Petrino. To better understand Colburn's situation and the concept of grayshirts, SB Nation spoke with FBS recruiting coordinators across the country. To address the situation directly, these coordinators requested anonymity.

What exactly is grayshirting? The term is derived from the official practice of redshirting. That's when a player is enrolled and practicing, but staying out of games for one season. Grayshirting is extreme redshirting. A player maintains his non-binding verbal commitment but does not enroll until the spring semester, so as to not count against the current year’s scholarship limit.

How common is it for a school to offer a grayshirt? Increasingly common. Just this cycle, we saw uses by schools like Alabama, Arizona, Auburn, Mississippi State, Texas, Utah, Western Michigan and Idaho, coached by Petrino's brother Paul, to name a few.

So grayshirting is an epidemic against helpless student-athletes? Not always. Motives can vary wildly. In some cases, a committed high school senior fails to qualify academically. Rather than enroll in a junior college, some players will opt to work on their academics and re-qualify for the following season.

Grayshirting gained national prominence in 2012 when two Alabama commitments were asked to take them after both happened to need knee surgeries. One, defensive lineman Darius Philon, declined and signed a scholarship with Petrino’s Arkansas Razorbacks.

Sometimes a player will grayshirt for the chance to play for a bigger program. Kansas State safety Ty Zimmerman opted to grayshirt rather than take a scholarship from a non-FBS school and ended up an All-American.

But neither of those examples applies to Colburn. Correct. According to coaches outside of Louisville, the three-star had no academic issues, was healthy and committed to U-L last June after receiving offers from Georgia Southern and Old Dominion.

So why did Louisville attempt to grayshirt Colburn? According to his high school coach, Colburn shut down his recruiting until he was told this month by Louisville defensive coordinator Todd Grantham that because three Louisville defensive backs declared early for the NFL Draft, the Cardinals needed more space to replace them. Colburn was asked to enroll in January 2016.

One FBS recruiting coordinator disagreed on the reasoning.

"More often than not, it's about perceived talent, what the coaches think. If they asked this kid to grayshirt, it's not because they're deeper at running back than DB. It's because they feel like he's the most expendable in that class regardless of position. A lot of times, and you're seeing it now more and more, offers are getting thrown out earlier in the recruiting process before a lot of staffs can really properly evaluate a kid."

"I think there was probably some apprehension there that had nothing to do with position," another coach said. "It was apprehension that they threw that scholarship out there in the first place."

Colburn and his Dutch Fork High School coach claim the scholarship was withdrawn, not delayed. Was it? That depends on how you view grayshirting.

Colburn committed last summer, thinking he would participate as a football player at Louisville in 2015. The Cardinals' stance (unofficially) is they didn't rescind the offer, they deferred it. Colburn is right to claim Louisville rescinded the exact scholarship it offered, and Louisville would be correct to claim that a grayshirt offer isn't a withdrawn scholarship.

Shouldn't Louisville have prepared for this DB situation earlier? It's not Colburn's fault he doesn't play corner, right? But the coaches we spoke with gave Petrino the benefit of the doubt. In his first year back, he inherited a roster recruited by the previous coach, Charlie Strong.

"It's pretty common to see attrition after your first season with someone else's players. You usually see it at the beginning of camp, then maybe a little in the year, and then another wave at the end of your first year. It's harder to predict when they aren't yours. These aren't your guys yet."

What was the fallout? Colburn was Mr. Football in the state of South Carolina. His high school coach said Louisville will no longer be allowed to recruit at Dutch Fork. South Carolina is a talent-rich area, but it's not the beaten path for the Cards, something that likely went into the decision.

"I don't think Louisville does that if the player is from Kentucky or nearby in Indiana or Ohio. You don't want to make a mistake, because those bans can stick if you're closer to home," one coach said. "You have to worry about the high school coach, not the player. It’s not only that school; it’s that area. You don’t know who [the coach] is friends with or close with, or if he’s close with guys in that local coaches' association."

How could this have been prevented? The coaches we spoke to disagreed on strategies. The first is to keep the commit and grayshirt a defensive back later on.

"Because [Colburn] was committed for so long, I'd say keep him, avoid the negative attention, and then try to add an extra DB after Signing Day. Maybe you get a preferred walk-on after spring practice ends. We're seeing more and more kids contact us after spring practices. That's a growing trend. You can find some talent there if they're willing to walk on."

The second involves more hindsight.

"You avoid the situation by not putting yourself in it. If you think after that amount of time you can live without a guy who has been committed, then you were wrong about offering him. The focus for the last few years has been about being first with scholarship offers when these guys are juniors. The better staffs have better evaluation processes.

"It's great to be first. It's better to be thorough."

"If they're lying about the little things, they're lying about the big stuff."

Would an early signing period prevent grayshirting? If football adopts the same kind of structure that basketball has, a player like Colburn could sign a National Letter of Intent soon after committing in the summer before his senior season. But that doesn't mean grayshirting would disappear.

"I think an early signing period would help because it might help pull more kids away from waiting until National Signing Day," said one coach. "The less top players you have doing that, the clearer your class is going to look. In [Colburn's] case, I think early signing would help because he committed a year before. But no, you're still going to have coaches offering grayshirts to help build depth. Even if they're down to just 10 scholarships in February instead of 25, or whatever."

What should recruits do to avoid this? According to a recruiting coordinator for a staff that competes for talent with Louisville, the growing trend is just another example of fading amateurism.

"My first reaction when I heard about [Colburn] had nothing to do with Louisville or with Coach Petrino. It was that now more and more people are starting to understand that college football is a business that affects a lot of people's lives on both sides. But the onus is on the university. At the end of the day, that’s a binding contract that affects someone’s life from that point moving forward."

Another coach suggested to evaluate coaches the same way they'd evaluate you as a player.

"Do your homework. Get on the Internet. Talk to as many people as you can. If they're lying about the little things, they're lying about the big stuff, like a scholarship."

"We tell these young men and their families it's all about relationships, that by the definition of the word commitment, there's no way the term decommitment can even make sense. My advice is to do your homework on the coaches that are talking to you. These things build a reputation."

Petrino already has quite the reputation. Is Louisville being unfairly targeted because of that? Petrino neither invented grayshirting nor stumps for it. While his stilted address of the Colburn situation on National Signing Day was quintessential animatronic Petrino ("This is the one time as a college coach you get to manage your roster," he said), he is no different than many others.

"Are they getting picked on because it's Bobby Petrino? Absolutely. Alabama's done it multiple times, and we're not talking about Nick Saban. Anything [Petrino] does now is going to.

"But that's my question. If you know that already, that Petrino gets attention, then why pull the scholarship? That's just another reason not to."