UEFA Champions League 2018-19: Four talking points as Barcelona face Liverpool at Camp Nou

#3 Liverpool's flying full-backs

Liverpool left-back Andrew Robertson

Neither Trent Alexander-Arnold nor Andrew Robertson have the star power of the frontline but the flying full-backs of Liverpool could play a vital role in this tie. With 24 assists between them in all competitions, the full-backs are pivotal figures in Klopp's gegenpressing.

Liverpool right-back Trent Alexander-Arnold

Robertson may have to deal with Messi from time to time as the Argentine usually starts from the right but when Messi drifts to the centre, the Scottish left-back will have to be at his peak as his runs up and down the flanks will give Sadio Mane the freedom to move infield.

#4 Mohamed Salah vs Jordi Alba

Mohamed Salah vs Jordi Alba

It does not get faster than this. Two of the fastest players in their respective positions will lock horns. Salah has found his goalscoring form in recent weeks as he leads the charts for the Premier League golden boot with 21 goals, one ahead of Sergio Aguero and teammate Sadio Mane.

Jordi Alba is a left-back who loves to bomb forward, which would leave Mo in acres of space. With 14 assists to his name, both Mo and Alba would have to think twice before they make their runs. It will be interesting to see if Alba forgoes his natural tendencies and link-up with Messi to keep Mo in check.