Martyn Rooney's World Championship hopes rest on whether his hamstring holds up at this weekend's British Championships.

The 26-year-old Croydon Harrier has not raced for a month due to a small hamstring tear taking longer than expected to heal, but will need to come through three races and win Sunday's final, which doubles up as the trials for the Worlds, and run the A standard time of 45.28 seconds to qualify for the Championships in Moscow next month.

His fastest time to date in a season dogged by injury is 46.00, but with Michael Bingham the current British number one in 45.37, the title is there to be won - if Rooney's hamstring stays strong.

"It's not been the easiest couple of weeks," said Rooney, who has won the British Championships for the past three years.

"I think it should be alright for this weekend but I am going to have to play it by ear and see what happens.

"My winter started four months later than usual as there were some issues with my hip that needed to be sorted post-Olympics.

"It took a long time to get back into training and the races I have done were more for training than times, though it would have been nice to get the A standard so it was out of the way.

"But no one has been running that quickly and the training I have done I have felt good.

"I know my fitness is there, it is now just about putting the race together and, even with the hamstring problems, I feel I can run something decent."

After failing to make last year's Olympic final, Rooney left coach Nick Dakin to join Rana Reider's team, after a brief stint with Fuzz Ahmed in Birmingham.

"I had been in Loughborough for seven years and felt it was time to do something different," he said.

"I was lucky to be part of Nick's group but I hadn't progressed in quite a while.

"I moved to Birmingham but I didn't like it, the set up didn't suit me as there was only really one other guy looking to be world class.

"So I moved back to Loughborough in January and began working with Rana, who has a lot of world class athletes in his group, including American Christian Taylor, who won triple jump gold in London.

"It is a very positive group of people and I feel it has made a massive difference and it is a shame I didn't start with him straight away."

Croydon Harrier James Dasaolu is also in action this weekend and will guarantee his World Championship place if he wins the 100m.