James, 39, who has won 50 caps to Green's 11, only discovered he was not being selected for Saturday's opening Group C clash with the United States five minutes before the players boarded their bus to go to the stadium before the game.
But after digesting his disappointment, James sat on the bench and saw Green, 29, make a shocking schoolboy blunder when he failed to save Clint Dempsey's tame shot as the United States levelled to claim a 1-1 draw.
England skipper Steven Gerrard had opening the scoring.
"I didn't speak to Robert straight after the game because he had to go for a drugs test," said James. "But I know that as a goalkeeper - and we all make a mistake like that sometime - you just have to put it behind you straight away and get on with the game.
COUNTER ATTACKED
"These things happen and he has to get over it. There is no time to dwell. It was one of those things and it changed the game because after that I thought the U.S. team shut up shop and only counter-attacked in the second half."
James declined to say he expected to play, but showed clear disappointment even if he accepted manager Fabio Capello's customary late decision to pick Green ahead of him and 23-year-old Joe Hart, widely regarded as England's most talented goalkeeper for the future.
"When the manager announced the team, I would not say it was a surprise, but there were people hoping to play who were not picked," said James, with a deliberation that hid his disappointment.
"Everyone wants to play and this environment - the way the manager likes to have things now - encourages an anticipation to play.
"It means that you don't know who is playing or not, of course, so that means you don't have two of the three goalkeepers knowing they are not going to play, as it was in the past."
James confirmed he was fit to play and that rumours of a knee injury last week, when he trained in the gym, were not accurate. "I was fit, we all were," he said. "All 23 of us.
"I am ready to play and, of course, I want to play. I have been around a while and this is not my first World Cup. But I know what it is like and I know what to expect.
"You come to the World Cup and you are disappointed to have the numbers 23 and then 12 on your back, but you have to work hard to play. As a professional, now, I have number one and I am still the man with number one even if I was not picked.
"So, like all the other players, when you know you are not playing you have to push to do everything right and not only help everyone else but push hard to get a game. That's the same for me as anyone else."
