Mark Lewis-Francis made an early exit in the 100m at the World Championships in Helsinki and then revealed he is a doubt for the 4x100m relay.
The Briton, who won Olympic relay gold last year, finished fifth in his 100m quarter-final in 10.53 seconds.
And the 22-year-old then said he was struggling with a hamstring injury that threatens his relay place.
"It's the same tear from 2002," he said. "I thought it would be okay but obviously not."
Fellow Britons Jason Gardener and Marlon Devonish both advanced to Sunday's semi-finals.
Gardener finished third in his quarter-final in a time of 10.31secs to qualify automatically, while Devonish was fifth in his race but went through as a fastest loser in 10.20secs.
Devonish said: "I'm pleased to be in the semi-final. I would have liked to have put myself in a better position because I am in better shape than 10.20secs."
Gardener added: "I'm not pleased to have lost the race but I've not seen anything spectacular from the other athletes so I look forward to challenging tomorrow."