For spending 80 hours a week on the job, NFL coaches could afford to use some of that time to read the rulebook.

I’ve never read the official rules of the NFL, but even I know what plays are eligible for instant-replay challenges.

One example comes from the Minnesota Vikings’ 23-16 loss to Green Bay on Sept. 30. Trailing late in the game, the Vikings appeared to be on their way to scoring a game-changing touchdown on a fumble recovery.

A Packers receiver caught the ball and ran a few steps before getting stripped. Vikings linebacker Chad Greenway recovered the football and had a clear path to the end zone. However, the play was clearly blown dead by the referees’ whistles and called an incomplete pass shortly after it hit the ground.

The refs got the call wrong in my book, but every avid NFL fan knows a play cannot be challenged once it’s blown dead by an official’s whistle.

Minnesota coach Brad Childress threw his red challenge flag to the turf, and FOX analyst Brian Baldinger was shouting something like, "They should challenge that. They have to," only to hear everyone get informed by a ref that the play was not allowed to be challenged.

This happens at least once a week somewhere in an NFL game. And it has been happening since the challenge system was put into play. Why is it that the guy on the couch knows what’s going on, but the people who get paid to work in and cover the NFL are clueless?

In no other professional sport do you see coaches and broadcasters confused on a weekly basis regarding calls and rules.

PICTURED: St. Louis Rams coach Scott Linehan. Photo by McClatchy Newspapers