Multiple world record holder in sprints Usain Bolt is a major doubt for the 2016 Rio Olympics in Brazil after he pulled out of Jamaica's National Championships trial due to a hamstring injury.
Bolt, who holds the world records in both the 100m and 200m, pulled out of the final of the 100m having been examined by a doctor who diagnosed a grade one tear in his hamstring.
The world and Olympic champion took to Twitter to explain his absence.
"After feeling discomfort in my hamstring after the first round last night and then again after the semi-final I was examined by the Chief Doctor of the medical team and was diagnosed with a grade one hamstring injury," Bolt tweeted on Saturday.
"I have submitted a medical exemption reminder to be excused from the 100m and the remainder of the national championships. I will seek treatment immediately and hope to show fitness at the London Anniversary Games on July 22 to earn my selection for the Olympics in Rio."