Famed for their counter-pressing style which helped Liverpool compete on all four fronts last season, Klopp's side have leaked goals this season and kept only two clean sheets in all competitions.
A 3-3 draw against Brighton & Hove Albion dropped Liverpool to ninth in the Premier League standings and Klopp said they would have to come out of the crisis in a similar way to when they lost several defenders to injuries two seasons ago.
Liverpool have won only three games this season and Klopp compared the squad's crisis in confidence to that of Cristiano Ronaldo, whose form tapered off and led to the Manchester United forward being benched.
Rangers lost both their group games without scoring to sit bottom of Group A and Klopp said he expects the Scottish side -- who lost the Europa League final on penalties last season -- to be pumped up after Saturday's 4-0 league victory over Hearts.