Arsenal manager Arsene Wenger has admitted he has 'taken a gamble' on new signing Amaury Bischoff due to the young midfielder's fitness issues.The Gunners announced the signing of the Portugal Under-21 international from Werder Bremen on Thursday afternoon. And Wenger admits that after two groin operations, it will be at least two months before the 21-year-old is ready for action. 'Amaury is a young, promising player who we have taken a gamble on because he has been out for a long time,' Wenger told arsenal.com. 'We have to get him to a very good [fitness] level. 'He has talent but we'll have to wait two or three months to get him competitive. He has had two surgeries on his groin so it is a gamble on his talent.'