7:30 a.m. ET: Get your quarters ready, the NFL head coaching carousel has begun.

The Monday following Week 17 in the NFL is casually (and somewhat sedistically) referred to Black Monday, as underachieving teams often cut bait with unsuccessful head coaches in what's the first day of the offseason for teams failing to reach the playoffs.

This season, though, things were a little bit different, though, as some teams couldn't even wait until Monday to send their head coach packing. The Cleveland Browns got the ball rolling by relieving head coach Mike Pettine and general manager Ray Farmer of their duties. Not long after that, the San Francisco 49ers struck, giving first-year head coach Jim Tomsula the ax.

Both of those are moves are in addition to the Philadelphia Eagles firing head coach Chip Kelly ahead of Week 17, meaning there currently are three head coaching vacancies, four, if you include the Miami Dolphins who finished 6-10 after Dan Campbell took over for Joe Philbin during the season.

More dominoes figure to fall on Black Monday, and we'll have all of the latest news and rumors, so be sure to check our Black Monday live blog throughout the day.

Thumbnail photo via Brian Spurlock/USA TODAY Sports Images