Former Olympic javelin thrower Steve Backley says Great Britain have had a "shocker" after failing to win a gold at the World Championships so far.
Apart from medallists Mo Farah, Jessica Ennis and Andy Turner, Backley said the team has underperformed in South Korea.
"We've got to go back to the drawing board and say 'what the heck is going on?' because it's serious and seems to be viral through the team," he said.
"We've had no PBs (individual events). We're having an absolute shocker."
Britain's head coach Charles Van Commenee vowed to deliver seven medals and at the halfway stage the team has won three.
Farah and Ennis came away with silver medals in the 10,000m and heptathlon, while Turner's 100m hurdles bronze came after winner Dayron Robles of Cuba was disqualified.
Triple-jumper Phillips Idowu is yet to compete and is also expected to medal as is Dai Greene in the 400m hurdles and Farah again in the 5000m.
But Backley, who competed in three Olympics and two World Championships told BBC Radio 5 live: "We can't dress it up. The fact of moving on and developing is being realistic about where you are.
"We can't be buoyant on what we've seen so far."