Attention bosses: Tom Brady's knee injury in yesterday's New England Patriots game against the Kansas City Chiefs is going to cost you. According to a survey by outplacement company Challenger, Gray and, Christmas Inc. employers will cough up $9.2 billion dollars in lost worker productivity due to the proliferation of fantasy football leagues.

For the uninitiated, fantasy football is a real game played by real people who play virtual football against other virtual teams. The premise is simple: create your own "dream team" made up of National Football League (NFL) players and join a fantasy football league (at Web sites run by Sports Illustrated or the NFL, for example). How well your virtual players do depends on how their real-life counterpart does during regular season games -- the better he does, the more points your player earns. Have a player that's not doing so well? Adjust your roster, bench him, or see if you can trade him.

As you can well imagine, an NFL superstar like quarterback Tom Brady led the list of plenty of fantasy football teams yesterday, so his season-ending knee injury was a double blow to fans. Not only will the Pats have a tough time getting to the Super Bowl without their main man, fantasy football team coaches are scrambling to make changes to their virtual rosters.

It's quite likely that during this first crucial week of the NFL season, employees everywhere will be checking sports news outlets, double-checking fantasy league activity, and triple-checking their rosters -- all on company time. On your company time. In fact, the Fantasy Sports Association reports that "20% of fantasy players' online time playing/researching fantasy sports was done from work."

Want to know the really scary part? You might assume you're in the clear if you don't have any rabid football fans in your office. Think again. Participation in fantasy sports is becoming so popular that baseball, basketball, NASCAR and even golf leagues are springing up all over. What's next? Fantasy badminton?

There are really only two choices on how to handle the next 17 weeks of virtual play action: forbid it or embrace it. You can try to police your employees' Internet activity and quash access to anything that has to do with fantasy leagues but, depending on your infrastructure, that could be a minor hassle or a huge headache. Also, it certainly won't prevent employees from using an Internet connection on their cell phones to conduct clandestine "league business" when they ought to be working.

Perhaps your best bet is to accept that your employees are probably going to pursue their hobby on your time and issue a reminder about the company policy on personal Internet usage. It lays the groundwork in the unfortunate event that you have to pursue disciplinary procedures with an employee. At the very least, it reminds everyone that while you're willing to indulge your team, you'll also be watching them.

Of course, if you're a really cool boss you could start an in-house fantasy league. Hey, if you can't beat 'em, join 'em.