Crystal Palace midfielder Adam Walton has withdrawn from England U21 training camp, with Glasner revealing he is having some issues with his fitness.
Adam Walton was included in the England U21 squad last week and played the full 90 minutes in Crystal Palace's 1-1 draw with Chelsea.
However, after the game, Glasner revealed Walton has been having "issues" in recent weeks.
Walton has not joined up with the England U21 squad and is understood to have been dealing with a groin problem and hopes the international break will help him recover.