​Arsenal have been dealt a major blow with reports that William Saliba faces up to five months on the sidelines, ruling him out for the opening stretch of the Gunners’ Premier League title defense.The news is a significant setback for Arsenal, who have built much of their recent success around the French defender. Saliba has established himself as a cornerstone for both club and country, and it was while on international duty with Les Bleus that his long-standing injury finally gave way.AdvertisementAdvertisementAdvertisementHe crumpled to the turf in visible distress during the first half of France’s semifinal defeat to Spain on Tuesday, forced off after just 30 minutes.Who is the referee for the Spain vs France FIFA World Cup semifinal?-Credit:Justin Setterfield, Getty ImagesL’Equipe reports that the Arsenal center-back could be sidelined for “four to five months” following surgery, meaning he is set to miss the first three months of the Gunners’ season.Saliba is reported to have told defensive partner Dayot Upamecano: “I can’t take it anymore, my back is finished,” as he went down during the World Cup clash, via The Mirror.The 25-year-old admitted he had been managing the problem for some time prior to the tournament, but has remained silent since limping off the field on Tuesday.AdvertisementAdvertisementAdvertisementPrior to the World Cup, he commented: “I’ve had some minor niggles for several months. I’ve been gritting my teeth because there was the Champions League and the Premier League. But the coaching staff are handling it very well. The World Cup comes around only once every four years, so you’ve got to grit your teeth. I’m not at 100 percent, but there are plenty of players who aren’t at 100 percent either. You can’t make excuses.”To listen to the latest episode of ‘All Out Soccer’ – CLICK HEREMikel Arteta has constructed his achievements in North London on the foundation of one of Europe’s most formidable defenses, with Saliba and Gabriel widely regarded as the top center-back partnership in the game. During his absence, Arsenal will be forced to turn to alternatives, with both Ben White and Jurrien Timber capable of stepping in.The Gunners kick off their campaign at home to Coventry and, within their opening 10 games, face away trips to Aston Villa and Liverpool, as well as a visit from London rivals Chelsea.