Liverpool’s night in Istanbul went from bad to worse as Alisson Becker was forced off injured during the second half of their Champions League clash with Galatasaray.The Brazilian goalkeeper appeared to hurt himself after rushing out to deny Victor Osimhen, staying on the turf for treatment before eventually being replaced by Giorgi Mamardashvili.Speaking after the match, manager Arne Slot confirmed that Alisson will not feature against Chelsea this weekend, sparking concern among supporters about how long the No.1 might be sidelined.Injury expert weighs inOn Wednesday morning, injury analyst @physioscout gave a breakdown of the possible situation, suggesting that the problem looked consistent with a hamstring issue.They explained: “From the video, it wasn’t easy to tell the exact problem, but based on his past hamstring injuries and the way it happened during a sprint, it’s very possible that this is a hamstring strain rather than just tightness.”According to the assessment, the severity of the strain will determine recovery time:Grade 1: 2–4 weeksGrade 2: 4–6 weeksGrade 3: 8–12 weeks (or longer)What it could mean for LiverpoolIf scans show a mild Grade 1 strain, the international break may limit his absence to just the Chelsea game. However, if it’s closer to Grade 2, Alisson could be out until mid-November—missing at least eight matches, including clashes with Real Madrid and Manchester City.The situation will be familiar to Reds fans, as almost exactly a year ago Alisson suffered a hamstring problem against Crystal Palace, ruling him out for over two months.Given his outstanding form before this setback, losing the Brazilian is a huge blow. Still, backup goalkeeper Mamardashvili, who recently impressed in the Carabao Cup win over Southampton, now has a chance to step up and prove himself.