FC Porto coach Sergio Conceicao reckons Liverpool are "the best team in the world" on their day as the Portuguese side face up to the daunting prospect of overturning a two-goal deficit in their Champions League quarter-final.

The teams meet at the Estadio do Dragao tonight in the second leg of their last-eight tie, with Porto needing a historic comeback to go through after losing 2-0 at Anfield last week with Naby Keita and Roberto Firmino scoring.