The 22-year-old, who cost just £250,000 when signed from Asec Mimosas of the Ivory Coast, has been a revelation in defence after arriving with the reputation as a midfielder of immense promise, but Wenger advised caution. "He has done well, the signs are positive," he said. "I never imagined him to be a central defender and I put him there in pre-season on instinct more than anything.