The popular wing-back has been ruled out of the rest of the season and this summer's World Cup Finals after suffering a setback on his road back from a knee injury. He has been told to rest for six to eight weeks.
Boss Glenn, without the two-times Player of the Year all season, said at Spurs Lodge on Thursday: "It's a big blow to the lad and you can only think of what he feels like.
"He's tried very, very hard to get fit and we actually got him back up to some decent football.
"He joined in with training but he just felt his knee was reacting after training.
"He went back to America and the good news is that the surgeon doesn't feel he needs to be re-operated on, which would have been a major problem.
"There is some scar tissue build up and other slight things that he feels with rest and good management will be okay.
"Now we haven't got to push him we can get him ready for next season. That's the plan.
"But at this moment in time it's a huge blow. Stephen's had a few days to think about it but it's a hard one because the World Cup is a bit special.
"The positive thing is that he's young enough, if Ireland can qualify again, to play in the future."
Glenn Hoddle says his heart goes out to Stephen Carr but insists the Irish star's day on the world stage will come.