Jose Mourinho is convinced Porto have every chance of producing a surprise and knocking Liverpool out of the Champions League.
Jurgen Klopp's side meet Porto in the quarter-finals on Tuesday, the first leg at Anfield on April 9, and will be full of confidence having beaten them 5-0 over two legs in last season's competition.
But Mourinho, who coached Porto to Champions League glory in 2003-04, feels his old side will be a different proposition to the one that was easily swatted aside last year.
'The tie is open and what happened last year, I believe, can play for Porto in both games,' Mourinho said at the ANTF Coaches Forum in Portimao.
'Compared with last season, I think Sergio Conceicao will ask himself questions about what happened in order to do something different this time around.
'Liverpool have absolutely fantastic individual quality, but they are disputing the league title which means that they will not rest players in the previous game or between the two games.'
Liverpool's primary focus is keeping pace with Manchester City in the race for the Premier League title and that leaves the door ajar for Porto to capitalise.
Conceicao's team are themselves engaged in a fierce battle for the title - level with rivals Benfica on 66 points after 27 games - but they will be determined to prove they have learned lessons from the mauling to the Reds last season.
Porto are rank outsiders against the high-pressing, energetic Liverpool side that were losing finalists in 2017-18.
As for Mourinho, he has been out of work since he was sacked by Manchester United in December and recently revealed he has turned down as many as four job offers since leaving Old Trafford.
Having enjoyed some media work since departing United, he has expressed a desire to return ahead of next season and he remains keen to add to his two Champions League titles - Porto in 2004 and Inter Milan in 2010.
