The Scotland international picked up the problem during the first half of the 3-0 loss to Liverpool , and he was substituted before the break. Arteta has now confirmed that Tierney won't require a surgery, but he is set to remain on the sidelines for up to six weeks. He told Arsenal .com: "We have to first make sure that he doesn't need any surgery, which it doesn't look like." "If that's the case, the timeframe will be around [four to six weeks]. It could have been worse because the action looks quite scary. "He's feeling better and the damage is not that bad. At the end of the day, it's not the bad news that maybe we were expecting after the game." In the absence of Tierney, Arteta has no specialist left-back in the squad. Either Cedric Soares or Bukayo Saka could feature in the role. Saka has excelled from the right-wing this term and it certainly appears that Cedric will get the nod for the defensive position. The Gunners are scheduled to host Slavia Prague in the first leg of the Europa League quarter-final on Thursday night.