The 25-year-old visually-impaired sprinter, whose family live in Langholm, withdrew from Sunday’s T12 200m semi-finals after injuring her foot in the warm-up.
And she and guide runner Mikail Huggins were also forced to miss yesterday’s 100m heats.
British Athletics tweeted yesterday: “Libby Clegg & Mikail Huggins have withdrawn from the T12 100m after an achilles injury sustained by Clegg in warm up yesterday.”
Speaking to C4 Paralympics, Clegg added: “Sport can sometimes be cruel, but this setback has given the motivation to come back stronger for Rio.”
Illness also forced Clegg, who scooped gold at the Commonwealth Games and a silver medal at the 2012 Paralympic Games, out of last year’s European Championships in Swansea and her 2015 season has been hit by injury.
The GB star, who is now based in Leicestershire, lives with a deteriorating eye condition known as Stargardt’s Macular Dystrophy, which gives her only slight peripheral vision in her left eye and means she is registered blind.