Roy Hodgson said it was an "unbelievably hard" decision to leave Ashley Cole out of his World Cup squad.
The England manager chose to include Southampton's 18-year-old left back Luke Shaw instead of the experienced 33-year-old Chelsea player.
Cole subsequently announced his retirement from international football as he wished England success at the tournament.
"It was an unbelievably hard decision because Ashley is a player I and the rest of my staff really appreciate. I think he is a magnificent player and what he has done for England is second to none," Hodgson said.
The 66-year-old said he was grateful for Ashley Cole's acceptance of the decision.