Wednesday 5 February 2020 12:29, UK
Sir Mo Farah has pulled out of the Vitality Big Half after suffering a minor Achilles injury.
The four-time Olympic champion has won the London race for the last two years and was due to face Ethiopia's Kenenisa Bekele this year.
But Farah - who announced he will return to the track for the summer's Olympics in Tokyo last November - will now not compete on March 1.
Farah said: "I was really looking forward to racing The Vitality Big Half again.
"Everyone knows how much I love racing in London, but my priority is to be fit, healthy and competitive for the summer season and for that reason I have had to make the tough decision not to race this year.
"I definitely hope to be back again in 2021."
Farah will continue his preparations for the summer in Africa, having opted to quit the marathon for another Olympic track title bid.
Farah won double gold over 5,000m and 10,000m at London 2012 and Rio 2016 before leaving the track to focus on marathon running in 2017.
He broke the European record to win the Chicago marathon in 2018, but could only finish fifth in London in April last year.
With world record holder Eliud Kipchoge an overwhelming favourite, a marathon victory in Tokyo was unlikely and Farah will instead look to defend his 10,000m title again.