Earlier this week, Tiger Woods said he had to withdraw from the US Open because of leg injuries. Two days later, prices for four-day tickets to the major tournament had dropped almost 20% on Stubhub, from $500 to $402. A company spokesman says he expects US Open ticket prices to drop another 17% before the tournament starts next Thursday.

“Missing Tiger is a big deal,” said company spokesman Glenn Lehrman. “He’s a huge draw, not only for tickets, but also for television ratings.” Lehrman did say ticket prices for this year’s US Open outside Washington, DC, are similar to last year’s, which was held at Pebble Beach and where Tiger finished tied for fourth.

“We are disappointed that Tiger Woods, a three-time champion, will not be able to play in the 2011 U.S. Open,” said USGA Executive Director Mike Davis in a statement on the association’s website on the same day Tiger announced he was withdrawing. “The excitement that he generates will be missed, but the Blue Course at Congressional Country Club will surely provide an excellent test for the 156 world-class players in the field.”

Tiger hasn’t won a major since the 2008 US Open, when he limped around on an injured leg to beat Rocco Mediate in a 19-hole playoff.