Arsenal full-back Kieran Gibbs will be sidelined for between four and five weeks after undergoing a hernia operation yesterday, manager Arsene Wenger has confirmed. The problem came to light after the 22-year-old sustained a stomach injury in training a month ago, and he now looks set to be out of action until around Christmas. Wenger told the Arsenal website: \"He has a hernia and had surgery on Thursday. He looks like he will be out for between four and five weeks. \"At first he had an abdominal strain, certainly caused by the fact that he had a hernia already. When the strain was healed we discovered that he had a hernia. We had a fear that could be behind it so we decided to do the surgery.\" Gibbs\' absence was not the only defensive blow for Wenger ahead of tomorrow\'s Premier League game at Norwich, with Carl Jenkinson suffering from a back problem. \"We have had some bad news because we have lost two full-backs over the break but apart from that all the players came back in good shape and everybody is available,\" Wenger said. \"Carl has a stress fracture in his back. That\'s just about rest now. We discovered that because he had a pain in his back. First you monitor it, then play a little bit and then you check again because you are cautious. \"We found a small stress fracture that we noticed at an early stage. If he continued to play it could have got worse and then he could be out for a long time. So at the moment the specialist has decided to rest him.\" He added: \"[Abou Diaby and Marouane Chamakh] are both back in full training again. Diaby has been out for four or five months so he will need some adaptation. Chamakh is available for the weekend.\"