Manchester United's contract talks with midfielder Paul Pogba have hit a new roadblock, causing club officials to fear he will try to seal himself a free transfer from the club next summer.United have already used the 12-month extension clause in Pogba's contract to stop him from leaving last summer, but despite an improvement in the general mood at Old Trafford since then, talks about a new deal have not yet yielded results.New reports suggested that Pogba's agent, Mino Raiola, was chasing a £ 400,000 a week salary for his…