Trayvon Bromell on his way to a 10.01 clocking in the 100m at the Texas Relays (© Kirby Lee)
With world junior record-holder Trayvon Bromell in their squad, the US is capable of breaking the 10-year-old 4x100m championship and world junior record, after missing the global mark by a hundredth of a second two years ago.
But Jevaughn Minzie and Michael O'Hara should propel Jamaica to a fast time and a run at dethroning the US as they did in 1998 and 2006.
Other contenders include Trinidad and Tobago, Japan and Great Britain.
Javier Clavelo Robinson for the IAAF
