Liverpool's Virgil van Dijk celebrates scoring their fourth goal during match Champions League Quarter Final Second Leg between FC Porto v Liverpool at Estadio do Dragao, Porto, Portugal, April 17, 2019. Liverpool beat Porto 4-1 at the Dragao Stadium on Wednesday to advance 6-1 on aggregate. Action Images via Reuters/Andrew Boyers

Liverpool's Virgil van Dijk scores their fourth goal during match Champions League Quarter Final Second Leg between FC Porto v Liverpool at Estadio do Dragao, Porto, Portugal, April 17, 2019. REUTERS/Rafael Marchante

Liverpool's Roberto Firmino scores their third goal during match Champions League Quarter Final Second Leg between FC Porto v Liverpool at Estadio do Dragao, Porto, Portugal, April 17, 2019. Action Images via Reuters/Andrew Boyers

Liverpool's Sadio Mane scores their first goal during match Champions League Quarter Final Second Leg between FC Porto v Liverpool at Estadio do Dragao, Porto, Portugal, April 17, 2019. Action Images via Reuters/Andrew Boyers

Liverpool's Mohamed Salah scores their second goal during match Champions League Quarter Final Second Leg between FC Porto v Liverpool at Estadio do Dragao, Porto, Portugal, April 17, 2019. Action Images via Reuters/Andrew Boyers

Liverpool's Mohamed Salah celebrates scoring their second goal during match Champions League Quarter Final Second Leg between FC Porto v Liverpool at Estadio do Dragao, Porto, Portugal, April 17, 2019. Action Images via Reuters/Andrew Boyers