PORT ELIZABETH, SOUTH AFRICA - MAY 07, Rene Kalmer leading the race during the SPAR Women's Challenge at Kings Beach on May 07, 2011 in Port Elizabeth, South Africa Photo by Reg Caldecott / Gallo Images

Johannesburg – Two of South Africa's best distance runners say they have made themselves unavailable for selection to compete at next month's IAAF World Championships as they are not confident of representing the country to the best of their abilities.

Middle-distance star Juan van Deventer and long-distance runner Rene Kalmer have both managed to overcome injuries which derailed their seasons, but would rather not represent the country at the highest level of competition until they are fully fit.

“I tore my calf muscle at the Boston Marathon in April and was out for a month, so the preparation period was too short,” Kalmer said on Thursday at the announcement of a new sponsorship deal between Garmin and the Nedbank Running Club.

“I'm always honoured to represent South Africa, and I would have loved to run in Moscow, but unfortunately I didn't have enough time to prepare.”

Kalmer, who had qualified to compete in the women's marathon at the global spectacle, would take part in local road races over the next few months, and was hoping to improve on her personal best of 2:29:59 at a major city marathon later this season.

“It's been a tough year, but now I'm healthy and injury free, and if it stays that way I'm confident I can run under 2:30 again,” she said.

“I'm enjoying my running at the moment and I'm motivated to set a new personal best.”

Van Deventer, who is Kalmer's teammate at the Nedbank club, said he had recovered from a knee injury but did not feel he was ready to take on the world's best in Moscow.

Van Deventer clocked 3:36.84 in Dessau, Germany, at the end of May, achieving the B-qualifying standard in the men's 1 500m, but was more than two seconds outside his personal best.

“I've been struggling with my knee and I don't want to go to the World Championships if I'm only 80 percent fit,” he said.

A former Olympic 1 500m finalist, Van Deventer was already looking ahead to next season and hoped to bag a medal in the men's 3 000m race at next year's World Indoor Championships in Sopot, Poland.

An accomplished athlete over a multitude of distances, Van Deventer holds the SA indoor 1 500m record and the national 3 000m mark outdoors.

“I'll run a few races on the road now, and I'm targeting the World Indoor Championships next year,” he said.

“With the speed I've developed in the 1 500m, I think I'll have a chance of winning a medal in the 3 000m final because it should be a tactical race.” – Sapa