By Nathan Ridley Jurgen Klopp has warned Liverpool that they could be their own worst enemies as the Premier League title race heats up. The Reds were bumped down to second place on Wednesday following Arsenal’s comfortable 2-0 win at home to Luton. Klopp’s side are also now level on points with Manchester City, who thrashed Aston Villa 4-1 thanks to a sublime Phil Foden hat-trick. Liverpool welcome basement dwellers Sheffield United to Anfield on Thursday, knowing that a win would take them back to the summit and restore their two-point lead with eight games to go. The Reds don’t have the adv…