James was substituted during Chelsea's win at AC Milan after jarring his kneeChelsea defender Reece James says he is "devastated" to not be included in England's World Cup squad.
The 22-year-old sustained the injury against AC Milan on 11 October but remained optimistic of recovering in time for the competition.
He began jogging this week after Chelsea had initially said he was expected to be out for eight weeks.
"The minute I injured my knee, I knew the turnaround to make the World Cup would be tight," James said on Twitter.external-link
"But I always felt it was possible.
"I've worked harder than I ever thought I could to give myself the best chance of going and truly believed I could help the team."
It is understood that England manager Gareth Southgate deemed it too big a risk to take James.
But James said: "I appreciate there was a risk on both sides, but it was one I was willing to take.
"Good luck to the boys. I'll be back soon. Stay safe and sending love."
England's World Cup campaign gets underway against Iran on 21 November.
Southgate's situation has not been helped by an injury to fellow England right-back Kyle Walker.
The Manchester City defender had groin surgery at the start of October, but told the BBC last month he was "confident" of being fit for the World Cup.
However, City boss Pep Guardiola said last week that the 32-year-old would not play for the club before the tournament starts.
