#3 Virgil van Dijk
Eyebrows were raised when Liverpool signed Van Dijk for £75 million - the highest transfer fee for a defender.
But he put the questions about his transfer fee to bed with his performances and the former Southampton man also remarkably improved Liverpool's leaky defence.
Liverpool likes to play counter-attacking football, which leaves behind gaps in their defensive third and teams tend to haunt the Reds by capitalising on them.
They shipped a lot of goals under such circumstances and lost many crucial points during the course of the season.
But the arrival of Van Dijk somewhat improved the situations for the Reds as he also keeps the team in shape with his strong leadership skills.
Liverpool have kept six clean sheets in the last 11 matches and the signs of improvement can clearly be seen.
AS Roma will try to score a crucial away goal during the first-leg at Anfield and Virgil van Dijk will be the biggest hurdle for the I Giallorossi (The Yellow and Reds) in their mission.