The home fans were angered by a series of decisions going against them.
"Myself and Pascal Chimbonda went in to make a block challenge and then a few things were thrown, luckily enough they didn't hit me," explained defender Michael Dawson.
"Didier went off and I am not too sure what hit him. For him to go off, something must have hit him. I could see some coins being thrown around me.
"If you get injured in the game that is part of football but you don't expect that kind of thing to happen."
The Spaniard remained diplomatic on the incident, insisting he did not see it, but he said: "This is very bad for the players and those who work in football. "But I did not see what happened. We have to be left in peace on the pitch and you can't have objects thrown because somebody could get hurt."