The club today revealed the Brazil international - who had impressed in recent matches following his August transfer deadline move from Fenerbache - was set to have surgery in his home country after suffering the injury in what was effectively a meaningless final Champions League group game away in Olympiacos last week.

Given Kieran Gibbs is not yet fully fit from his hernia problem, while both right-backs Bacary Sagna and Carl Jenkinson are also sidelined, Gunners manager Arsene Wenger fielded four centre-halves along the backline against Everton.

Young Spaniard Ignasi Miquel is another option, although the 19-year-old reserve captain's more natural position is in also in the middle, and the Gunners could now look to bring in some experienced cover, perhaps on loan, when the transfer window opens again in January.

Santos, 28, is not expected to be available until mid-March at the earliest.

A statement on the club's official website, www.arsenal.com, read: "We can confirm that, following investigations and subsequent medical opinions by club specialists, left-back Andre Santos will have surgery to repair ligament damage in his right ankle sustained in the game against Olympiacos last week.

"Andre will have surgery in Brazil this week and is expected to be out for around three months. Everyone at the club wishes him well."

Wenger will also have some juggling to do in the Arsenal frontline at the start of 2012.

Gunners captain Robin van Persie netted a brilliant volley to beat Everton at Emirates Stadium and cap off the club's 125th anniversary celebrations on Saturday with a seventh win from eight Barclays Premier League games.

The in-form Dutchman, who now has 19 for the season and 33 Premier League goals in 2011, has been well supported by both England winger Theo Walcott and Gervinho.

However, the Ivory Coast forward is set to head to the African Nations Cup in January, which could see him unavailable for selection for the best part of two months.

While Wenger admits his back-up attacking options will be stretched, as Marouane Chamakh is also set to be away with Morocco, Arsenal boss has ruled out bringing in any more forwards during the transfer window - preferring instead to give South Korea captain Park Ju-young and Russian Andrey Arshavin the opportunity to impress.

"The problem for us is we lose Chamakh in January, we lose Gervinho in January, and offensively we will be a bit short," Wenger said.

"However, we have Arshavin, and we have [Alex] Oxlade-Chamberlain, who has made great progress already, who can come in. We also have Park, now his adaptation period is over, we will see much more from him in the second half of the season."

Chamakh was a hit in his first campaign with the Gunners following a free transfer from Bordeaux, and scored 11 goals.

However, given the prolific form of van Persie, the 27-year-old has now found chances limited - with just one start in the Premier League and a single strike in the 4-3 defeat at Blackburn in mid-September.

While the 6ft 2ins striker remains part of Gunners boss Arsene Wenger's long-term plans, Chamakh accepts sooner or later he has to get more game time.

"I am 27. I need to play. I cannot stay like this forever," Chamakh told French TV station TF1's 'Telefoot'.

"If I played more, of course I would have more confidence and score more goals."

Chamakh revealed he would have an "important decision" to make in the summer, and indicated if he were to return to France one day in his career, Bordeaux would be the preferred destination.

Arsenal are, meanwhile, currently exploring all options for next summer's pre-season campaign following the decision to postpone the Emirates Cup because of a clash of dates with the London Olympic Games.

A delegation from the club is understood to have arrived in Lagos, Nigeria as they examine several potential destinations ahead of a final decision in due course.