Mason was an unexpected medallist at the Beijing Olympics
Olympic high jump silver medallist Germaine Mason has withdrawn from the Great Britain team for the World Championships with an ankle injury.
The Jamaican-born 26-year-old suffered ligament damage in his take-off leg at Friday's Grand Prix in Stockholm and is out for the rest of the season.
UK Athletics chief Charles van Commenee admitted: "It is a blow for the team."
European Under-23 200m champion Toby Sandeman is also out of the Berlin event, which starts on 15 August.
The 21-year-old produced one of the biggest shocks at the World Trials and UK Championships in Birmingham last month when he won the 200m.
He followed that a few days later with victory at the European Under-23 Championships in Lithuania but has been forced to pull out of the World Championships citing a lack of fitness due to an ongoing foot problem that has hampered his training.
Van Commenee said: "Toby has been receiving treatment and has been unable to train over the last couple of weeks and of course that is not ideal preparation for the World Championships.
"And the loss of Germaine, a proven championship performer, is particularly disappointing, but his injury, sustained in competition, is unfortunately an occupational hazard.
"However, we need to look ahead to the championships and our focus is on the final preparations for those competing in Berlin."