The men’s 100m event at the IAAF World Championships took another blow today with the announcement of Asafa Powell’s withdrawal.

Powell, who leads the world rankings this year with 9.78, had been expected to be one of the biggest challengers to fellow Jamaican Usain Bolt. But the former world record-holder will not line up for the 100m heats when the championships get underway on Saturday.

The first question mark over Powell’s participation came when he pulled out of the recent London Diamond League meeting, citing a groin injury. The same injury has now kept him out of the World Championships.

Powell was meant to be taking part in the Jamaican press conference, which was held earlier today, but his no-show added further intrigue.

This is the latest in an ever-growing list of big-name drop outs of the short sprint in Daegu. Earlier in the year American Tyson Gay brought his season to a premature end after aggravating an injury at the US Trials.

More recently Jamaica’s 9.80 man Steve Mullings failed a drugs test, while American Mike Rodgers tested positive for a stimulant.

It all means that Bolt will have an easier ride than originally anticipated when he attempts to defend his 100m title in Daegu. Had all athletes been fit and present, Bolt could have been under a lot of pressure.

The sprinting superstar may still be pushed all the way by the likes of US champion Walter Dix and Jamaican team-mate Nesta Carter, who finished just 0.02 behind him in Monaco.

Joining Carter and Bolt on the Jamaican 100m team will be 9.88 man Michael Frater and Bolt’s training partner Yohan Blake.

It has been suggested, however, that Powell may still take part in the 4x100m relay.