Clock ticking down on Bolt

First race in six weeks will show if he's ready for Beijing

After a six-week injury break, Usain Bolt returns to action in the 100 meters on Friday's opening night of the London Diamond League meet with question marks hanging over his fitness and form just four weeks ahead of next month's world championships in Beijing.

Like Mo Farah and Jessica Ennis-Hill, the British stars of the two-day Anniversary Games, Bolt will be hoping to find the Midas touch that took him to Olympic gold on the same London track in 2012.