Former Olympic champion Jason Gardener believes Great Britain have a realistic chance of winning medals at the World Athletics Championships despite taking a depleted and inexperienced squad to Osaka.

Gardener, who retired after making his last competitive appearance at Crystal Palace on August 3, is hopeful that the squad will bounce back from their miserable showing at the last Championships in Helsinki in 2005.

“I think we have some brilliant medal chances," he says. "Marlon Devonish is in the form of his life and in excellent shape although I don’t think he is capable of challenging the Americans in the 100 metres. Tyson Gay and Asafa Powell are in a different league to anyone else.

"But I expect the squad will do well. We will get a medal from the men's 4x100 metre relay. I don’t know how serious his back problem is but Phillips Idowu can compete, there’s no better time for him to take advantage of the field especially with Christian Olsson pulling out through injury.

"The women’s heptathlon and the 4x400 metre relay will also be interesting. I think Kelly Sotherton and Jessica Ennis can achieve. Lee McConnell and Paula Fraser are fine athletes and Nicola Sanders absolutely annihilated the competition at the European Indoor Championships."

Dave Collins, the UK performance director, has already bemoaned injuries to medal hopes such as Paula Radcliffe and Nathan Douglas that have left "too many cars in the garage". Gardener, however, says that the target set by UK Athletics of just three medals and 14 final places sells the team a little short.

"It will be a nervewracking time for Dave Collins with the number of injuries we have because he is going to be judged on results," he asserts. "But I think that underestimates our prospects. We’ve come a long way from Helsinki. I think we can win four or five medals but, with the limitations of the squad, eight to ten finalists is more realistic."

"If you look at the likes of Michael Rimmer in the 800 metres or Martyn Barnard in the high jump, the talent is still out there. There's no hiding place at the World Championships but we will have athletes who can make big names for themselves in Osaka. It’s all about the Championships – nobody will remember if you win at the AAAs – here you can show your true potential.

"Jessica Ennis has been so exciting to watch this year and, although Carolina Kluft has been unbeatable in the heptathlon, how much longer can she go on? Kelly Sotherton won’t just roll over and die and I expect a really good contest."

Great Britain's 4x100 relay team remain the best hope of a gold medal although an American team including Gay and Mark Jelks will provide extremely tough competition.

But Gardener, who believes that the British line-up should be Devonish, Christian Malcolm, his former training partner Craig Pickering and Mark Lewis-Francis, thinks that under the stewardship of the technically astute Michael Khemel, they can surprise everyone, despite doubts over Malcolm's fitness.

"Anything can happen in a relay," he says. "We learned that at the 2004 Olympics where no-one gave us a hope of winning. We had bags of team spirit. It's such a fine balancing act to keep a relay team firing but we were all so up for it. The American press were very negative about their team afterwards and they learned from that."

“Michael is a brilliant coach, the best appointment UK Athletics have made for a long time. Being Russian he is very methodical and looks at every angle of training and approach."

Khemel is hoping to use the experience of a disastrous baton drop at the recent Norwich Union Grand Prix at Crystal Palace to inspire the squad to victory.

"What happened at Crystal Palace is that we were caught off guard. Marlon and Craig Pickering were both very tired and I think the team were very cautious," Gardener says.

"You don’t want to risk injury before such a big tournament. It’s probably a good thing the drop happened there and I don’t think they’ll make the same mistake again."

Gardener is circumspect on the ending of his own career. He would loved to have given the Championships one last shot. “Well, good things come to an end but it was the right time to go," he says. "My body was telling me it was time to quit and I didn't think that the intensity of the sprints in Japan coupled with me leading off the relay would be conducive to my Achilles problem.”

“I’m just looking forward to putting my feet up and getting a proper job!"

British Eurosport is televising the World Athletics Championships live every day from 11am.