The 19-year old shot-stopper signed a four year contract on Monday and transfers with immediate effect from Belgian 1st Division side KRC Genk. Both clubs were keeping silent about the size of the transfer fee.
"We are pleased to have signed such a talented young keeper in Koen Casteels. He belongs to the top group of talent in Europe in his position", says director of football Ernst Tanner. Casteels will be given the number 30 shirt.