Usain Bolt's road to Rio just got a bit bumpy. 
 
The world's fastest man had to pull out of the 100-meter final at Jamaica's version of the Olympic trials because of a minor hamstring injury. 
 
In the United States, if an athlete fails to qualify in the trials, he's left off the Olympic team. 
 
But Bolt has a backdoor: In Jamaica, he can apply for a medical exemption, and if he shows he's healthy at a meet in London later this month, he can still make the team. 
 
In fact, it appeared that he was already working on it: