After a U.S. Open victory that was perhaps the most thrilling of his entire career, Tiger Woods will miss the rest of the season to undergo surgery to repair a torn ligament in his left knee.

Obviously this is bad news for his main sponsor, Nike (NYSE: NKE). They pay him handsomely to hit their clubs and wear their hat (although his bag bears the logo for Buick), and watching a close-up of his 18th hole birdie was priceless marketing: as the ball rolled, the Nike swoosh was in plain view.

And in a larger sense, this is bad news for anyone who's marketing on the PGA Tour. It's a well-known fact that golf's ratings plummet for any event Tiger isn't playing in. I mean, who really cares about Justin Leonard and Geoff Ogilvy? There's Tiger and then there's everyone else. Wake me when it's over -- maybe I'll go watch some arena football.

Without Tiger, all the other companies with players on the PGA Tour -- TaylorMade, Callaway (NYSE: ELY), Ping, etc. -- will get less exposure for their marketing money. And then there's KPMG, which pays Phil Mickelson to wear its hat. But then again, if a company you own shares in chooses its auditor based on Phil's hat, you have a lot more to worry about than Tiger's left knee.

But maybe there's a bright side here for the golf industry: perhaps a less exciting PGA Tour will inspire duffers to go out to the links and play some actual golf.