Liverpool will come up against former Anfield favourites Luis Suarez and Philippe Coutinho in the Champions League semi-finals.
The Reds secured their place in the last four of the competition with a 4-1 away win against Porto, completing a 6-1 aggregate success.
They will now face Barcelona in a mouthwatering semi-final following their thrashing of Manchester United on Tuesday.
Suarez and Coutinho have both not played against Liverpool in a competitive match since their moves from Anfield to the Nou Camp.
Coutinho left in a £140m deal in January 2018 while Suarez ended his stay on Merseyside in the summer of 2014.
Jurgen Klopp's response when asked how he's planning to stop Lionel Messi
Both are likely to feature in the two legs, fitness permitting, and Jurgen Klopp was asked about the proposition of taking on two former Liverpool stars.
"Honestly, the only thing I am thinking about is Cardiff on Sunday," the Reds boss said.
"For these two boys, it is very special, because they are Liverpool legends.
"But I don't think it will be a friendly game, we have to fight and work and they will do that as well.
"It is a wonderful game, Liverpool vs Barcelona in the semi-finals. Now let's try to do the best there and we will see what happens."
Jordan Henderson makes admission after Liverpool's win over Porto
Barca also face the unenviable task of trying to stop Lionel Messi with the Argentine scoring twice to down United at the Nou Camp.
On coming up against the Barca skipper, Klopp added: "Thank God I don’t have to think about that tonight. I have a few nights.
"No one has so far managed it but we will try. We have a few jobs before that."
