If you've watched any Patriots game over the past few years, you've probably noticed the epic beard that belongs to defensive coordinator Matt Patricia. 

Although no one seems to know for sure when Patricia decided to start growing out his beard full-time, it appears to have started at some point before the 2014 season. Since then, Patricia has been rocking the beard on the Patriots' sideline for the past four seasons. 

NFL: New England Patriots at Tampa Bay Buccaneers
Matt Patricia hasn't always had his beard.  USATSI

Of course, Patricia hasn't always had the beard, and if you've ever wondered what he looks like without his facial hair, we now have the answer. 

Here's a somewhat shocking photo of the almost unrecognizable Patricia with no facial hair. 

Patricia was hired by the Patriots in 2004 and that undated photo was definitely taken early in his tenure with the team, because he's been slowly adding facial hair since then. 

If you're thinking to yourself, "I probably wouldn't have time to shave, either, if I worked for Bill Belichick," that seems to be a popular theory with Patricia's beard. 

Former Patriots linebacker Niko Koutouvides, who played for the team in 2011 and 2012, recently told the Detroit Free Press that his theory on the beard is that Patricia is in his office so much that he just hasn't had time to shave. 

"I don't know the story behind the beard, how it ever came to fruition," Koutouvides said. "I just thought because he was in his (bleeping) office probably day in, day out, that thing just started growing and took a life of its own and he was like, 'You know what, I kind of like this thing, let's keep it going.'"

Patricia is expected to be hired as the Lions' new coach after the Patriots' season ends, and if he decides to keep his beard, he'll be one of a very small group of head coaches in the NFL who sport a fully grown beard (Mike Tomlin currently has one, and Mike McCarthy has been known to grow one whenever he feels like it).