Think about it this way: among all the great U.S. talents, which of them would you think had the top chances for a 1500m medal, if healthy and in the race?
Lagat (2009 double medalist, 2007 double gold (take note Brojos, not Spivey))--not competing
Wheating (1:44 and 3:30.9 in his first Euro race, and a many time NCAA champ)--injured hamstring and earlier calf
Webb (1:43.8 (1st)/3:30 (1st/WL)/3:46.91(WL))--injured
Manzano (3:32/World Cup medal/has won on the circuit)--flamed out early
Lomong (3:32)--didn't qualify
Centro (3:34 pr/NCAA champ/3:36 at 19)--US champ and bronze medalist
GF (3:39 NCAA champ as a frosh/solo 3:55i as a frosh)--injured and/or underperforming the past two years
Robbie Andrews (1:44/3:40 (closing fast), NCAA champ, a great future in this event--disappointed in the 800m at USATF after a great season.
David Torrence (1:45/3:34?)--didn't qualify.
It would have been hard to rank Centro near the top of this group, and there are others out there, but this is why we needed to produce depth at the top level, because without that depth we would just have a bunch of injuries and lesser talents representing us at the World's.