The NFL was hit by what seemed like an unprecedented rash of serious injuries in Week 8. No matter what game you were watching over the weekend, you probably witnessed at least one player go down with a serious injury.

The Steelers lost Le'Veon Bell for the season, the Chargers lost wide receiver Keenan Allen, the Ravens lost Steve Smith, the Saints lost Khiry Robinson, the Dolphins lost Cameron Wake and those are only a handful of the injuries that were suffered in Week 8.

Are all of these injuries a coincidence or is something causing them?

Former NFL quarterback Brady Quinn, who was the 22nd overall pick in the NFL Draft, on the Roughing the Passer podcast on CBS Sports this week offered a theory on why so many players are going down with injuries.

Quinn thinks the problem might have to do with supplements like HGH that make players bigger but also make them more prone to injury.

"I'm not going to be a whistleblower and I'm not accusing anyone of anything," Quinn said. "There's got to be something these guys are taking. That's what I think at least."

The former Browns quarterback thinks that skirting the HGH test has gotten easier for some players.

"When you're the starter, you have your annual [test] and you have one surprise [test] or one unknown [test]," Quinn said. "But beyond that, you don't get tested quite as often. It's really the backups or older players."

Colts quarterback Matt Hasselbeck would definitely agree with the second part of Quinn's statement. The 40-year-old has been drug-tested twice in the past six months.

Although Quinn thinks HGH is likely playing a part in this recent rash of NFL injuries, he wasn't accusing anyone specifically of using the illegal substance.

"I'm not accusing anyone," Quinn said. "But I think the usage of of HGH or performance enhancing drugs or supplements is greater now than it's ever been because the money is bigger now than it's ever been and the punishment isn't really that bad if you think about it."

With so much money on the line, Quinn believes that some players are willing to take a four-game suspension as a type of investment into themselves.

"If you're a top-of-the-line guy and you're getting $16 million a year -- you're getting a million bucks a game -- if you get popped for taking something that helps you get that big-time contract or hit that incentive in your contract where you get paid all of the sudden in your contract year, guess what? First [failed test], four-game [suspension]," Quinn said "Let's talk about financially, 'Am I going to sacrifice $4 million in order for me to get that big contract on the back-end? Yea, I am.'"

Quinn told CBS Sports senior NFL writer Pete Prisco that he believes "40 to 50 percent of guys are taking something" they shouldn't be taking.

Pat Kirwan, who's been working in the NFL for more than 30 years and served in the Jets front office from 1989-97, thinks HGH use is prevalent because it's easy to hide.

"When I first got into the league, it was the steriod era so that was a whole different world," Kirwan said. "I think the subtlety of HGH has encouraged more guys to try it and get involved. I think a lot of guys feel like if they don't, they won't be in the league."

Just because players are getting injured doesn't mean it has to be HGH use, though. Quinn also had several other theories on why guys are going down this season.

"It could be tied to a number of things," Quinn said. "As a player, you obviously realize that there are certain surfaces that are faster, a little grippier than others. I think the synthetic turf now-a-days tends to be a little faster and grippier, I think that could be a cause. You could say it's the footwear."

Those are on-the-field issues, but there are also off-the-field issues that could be causing the injuries, too.

"You could say it's what they're taking, supplements and things that they're putting in their body that are dehydrating their body and making them a little more tight and brittle, those sorts of things," Quinn said. "Or it could be a matter of overtraining in the offseason, not giving their body enough rest and all of the sudden, they try to come into the season and their ligaments and joints and things have so much wear-and-tear and they haven't received the proper amount of rest and attention they need."

Whatever the cause is, it's something the NFL needs to keep its eye on because too many injuries is something that's not good for players, teams or the game in general.

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Brady Quinn [center] has a theory on why the NFL has been hit with so many injuries this year. (USATSI)
Brady Quinn (center) has a theory on why the NFL has been hit with so many injuries this year. (USATSI)