Gareth Southgate says it may have been perceived as "arrogant" to select Reece James for England at the World Cup with "too many unknowns" over his recovery from injury.
The Chelsea full-back was left out of England's 26-man squad for the World Cup, which starts on November 20 in Qatar, after being sidelined since October 11 with a knee issue.
James sustained the injury in a Champions League clash with Milan and, despite no initial concern, scans revealed damaged ligaments could keep him out for up to eight weeks.
The 22-year-old still hoped to make England's travelling party but Three Lions manager Southgate opted to leave the right-back out due to the unknown nature of his recovery.
"We had to make a very difficult call with Reece, who is a fantastic player," Southgate said.
"He was not going to be available – if everything went perfectly – until the latter stages of the tournament and there were too many unknowns for us on that road to recovery."
Kyle Walker was still selected despite not playing since limping off in Manchester City's derby-day victory over Manchester United on October 2.
Southgate suggested Walker has made more encouraging progression in his recovery as he claimed including James may not be looked upon favourably due to issues over his group-stage availability.
"I do not think we can take a player who is not available for the group stage, that would be deemed arrogant in some circles," the 52-year-old added.
"But if everything went well and he was available, we would be dropping him into a quarter-final after eight weeks out. That would be really demanding. So it was a tough call.
"Kyle is a long way ahead of that and is progressing really well."
England face Iran in their World Cup opener before Group B fixtures against the United States and Wales.