Arsenal winger Theo Walcott has flown home from the club\'s training camp in Germany after the recurrence of a niggling ankle injury, the club confirmed Wednesday. Walcott, 22, returned to London for further \"investigation\" of the injury manager Arsene Wenger said as the Gunners prepare for their season-opening Premier League game against Newcastle next month. \"Theo went home early and was due to have an MRI,\" Wenger said on Arsenal\'s official website. \"It is an ankle injury that comes and goes. We need some more investigation because sometimes he\'s completely free of it and sometimes it affects him. But we had to send him back because he couldn\'t practice anymore.\" Wenger also revealed youngster Conor Henderson -- stretchered off in Saturday\'s 2-1 win over Cologne -- faced up to six months out after suffering a serious knee injury. \"Conor has a knee injury and it looks as if it is a cruciate. That means unfortunately that he will be out for six months at the very least,\" Wenger said.