Jeremy Wariner, two-time world champion and 2004 Olympic champion in the 400 meters, will not compete at this month's World Track and Field Championships in Daegu, South Korea.
Wariner's coach, Clyde Hart, said by telephone Tuesday afternoon, "It is my understanding Jeremy Wariner has ended his season early because of a foot injury."
USA Track & Field confirmed Tuesday night that Wariner had withdrawn from worlds, as first reported by the Tribune.
Hart said Wariner has ligament damage in the second toe of his left foot. The coach likened the injury to turf toe and said it does not allow Wariner to push off the foot the way he needs to.
Doctors have advised Wariner to take a couple months off to let the injury heal completely, Hart said.
The coach said Wariner did not want to risk jeopardizing the 2012 Olympic season.
"Right now, my focus is to get healthy, prepare for the 2012 season and try for my second Olympic gold medal in the 400," Wariner said in a statement from USATF.
After dominating the 400 meters from 2004 through 2007, when he won the second world title, Wariner fell behind another U.S. runner, LaShawn Merritt, who won the event at the 2008 Olympics and 2009 worlds.
With Merritt still sitting out a 20-month suspension for doping, Wariner lost the 400 at June's U.S. Championships to Tony McQuay.
Merritt returned from that suspension last week to clock 44.74 in finishing second at the Stockholm Diamond League meet. That time is faster than Wariner's season best of 44.88.
Wariner, 27, regularly broke 44 seconds from 2005 through 2008 but has not run that fast since. He nevertheless finished 2010 as the world's top-ranked runner in the 400.
His absence from worlds will complicate matters for the United States' 4 x 400 relay. Wariner has helped the U.S. win golds in that relay at the 2008 Olympics and both the 2005 and 2009 world championships.
Jamaal Torrence of Orlando, who finished fourth at nationals, will get Wariner's spot in the open 400 at worlds.