Mo Farah has pulled out of Sunday's London Marathon, citing a hip injury.
Farah, 39, was due to compete in the marathon for the first time since 2019. The four-time Olympic champion has taken part in the London event three times.
"I've been training really hard over the past few months and I'd got myself back into good shape and was feeling pretty optimistic about being able to put in a good performance at the TCS London Marathon," Farah said in a statement.
"However, over the past 10 days I've been feeling pain and tightness in my right hip. I've had extensive physio and treatment and done everything I can to be on the start line but it hasn't improved enough to compete on Sunday.
"It's really disappointing to have to withdraw after a good last few months and after my win at The Big Half but also because I love racing in front of my home crowd in London who always give all of us athletes such amazing support.
London Marathon event director Hugh Brasher said: "We are so sorry that Sir Mo is not fit to run on Sunday. We wish him a very speedy recovery and hope to see him running the 2023 TCS London Marathon in April next year."