Arsenal manager Arsene Wenger has confirmed that Santi Cazorla will be out of action for between three and four months after revealing that the Spanish midfielder has undergone surgery following a rupture of the external knee ligament. The French boss has also confirmed that Alexis Sanchez has travelled to Chile to have a mid-season break to recover from a hamstring problem.

Wenger claimed on Friday that Cazorla could be on the side-lines until March after he damaged knee ligaments during the draw at Norwich City. Speaking after the 3-1 victory over Sunderland, the the boss has now confirmed the worst fears that the Spaniard has been force to go under the knife.

"We know now it is a rupture. It's not the season (over) but it is at least three months, maybe four. He has had surgery, 48 hours ago. I was told yesterday," he said. "He wanted the chance to come back quickly so he didn't want to wait for 25 opinions, so he decided to go straight away. The guy said it's a clear case. It's a rupture of the external knee ligament, so he said 'OK, let's do it straight away."

Wenger has explained the decision to let Sanchez go back to his homeland to recover from the hamstring issue he sustained at Carrow Road.

"No (it is not risk), he is used to working there with the national team physio. I think it will have a double benefit," the boss added. "He will not be miserable here, he will be well treated there and it will give him a kind of mid-season break, which you all want!"

The pair and Francis Coquelin will miss the Champions League trip to Olympiakos on Wednesday 9 December where the north Londoners need a victory by two goals - or by one goal if they score three – to progress to the last 16. Wenger, however, is still confident the Gunners squad can cope with their absences.

"Personally it means a lot because it's important for the club and for the players," he said. "I want to win and I want to qualify. For me our job is to win the next game, and do what is requested. There is one positive thing for us - we know exactly what we have to do. We know that we have to go for it from the start. So let's do that and hopefully we can get through."