KINGSTON - Triple Olympic champion Usain Bolt could have an unexpected challenger when the Jamaican world record holder runs his first 100 metres on Saturday.

Asafa Powell, who held the world record before Bolt became athletics' biggest star, is considering switching from the 200 to the 100 at the Jamaica International Invitational because of a minor groin injury.

Meeting official Donald Quarrie said no decision had been made, but the sprinter's agent said they are evaluating all options.    

Powell originally had been scheduled to run the 200 against 100 metres world champion Yohan Blake, but the groin injury has the world's third fastest man contemplating a move to the shorter, less stressful distance.  

"If I don't run the 200 and get in the 100, that would be fine with me because this is what I'm training for and I have to be ready at anytime," Powell told Reuters. "I feel good so we'll see."

With the London Olympics less than 85 days away, Bolt is hoping to make the race a test of his preparations with or without Powell. His only race of the season has been a 4x100 metres relay.

"I continue to work towards the Olympics with one aim in sight: defending my titles," the world 100 and 200 metres world record holder said. "I am just working at keeping injury free and putting all the hard work together at the right time."

Saturday could be an early look at that work, especially if Powell joins a field that already includes 2008 Olympic silver medallist Richard Thompson of Trinidad and Tobago, talented Jamaicans Nesta Carter and Michael Frater and Antigua Olympian Daniel Bailey.

The women's 100 also is expected to be a fast one with American world champion Carmelita Jeter expected to face world bronze medallist Kelly-Ann Baptiste of Trinidad and Tobago and Olympic silver medallists Kerron Stewart and Sherone Simpson of Jamaica.

There are also strong line-ups in the women's 400  where Olympic champion Christine Ohuruogu of Britain faces 2009 world champion Sanya Richards-Ross and the men's 400 hurdles where American Bershawn Jackson will oppose Jamaican Danny McFarlane.