Alisson had a special message to Liverpool fans as he looks set to make his return to first team action on Sunday against Manchester United. Liverpool were dealt a huge blow on the opening day of the season when Alisson went down in the match against Norwich with a calf injury. He has been sidelined ever since, with summer signing Adrian stepping in to fill the vacant spot in goal. And the Spaniard has performed exceptionally well, helping Liverpool maintain their 100 per cent win record through the opening eight games. But now Liverpool’s back line looks set to be restored to full strength in time for their away trip to Old Trafford on Sunday (4.30pm). Pictures emerged on Monday of Alisson returning to training at Melwood alongside his Liverpool team-mates. The Brazil international took to Instagram to post a poignant photo of him fully kitted out in Liverpool training gear, looking up in the sky with his arms held out wide. There were two other photos accompanying the post of him in action, with the caption: “Happy to be back!!!” Adrian, who will drop to the bench against United, commented on the post: “Welcome back.” While Liverpool have won…