LOS ANGELES - A US team stung by two high-profile injury absences and a late doping case still sends a squad with eight reigning title holders to a 2011 World Championships seen as a springboard to 2012 Olympic success.

The loss of injured sprinter Tyson Gay and 400m star Jeremy Wariner were undoubtedly blows to an American squad trying to reassert its dominance over Jamaica in the sprints and match, if not improve on, its haul of 22 medals - 10 of them gold - at Berlin in 2009.

Gay's injury withdrawal from the US trials robbed the US of the American reckoned most likely to challenge Jamaican sprint superstar Usain Bolt.