New signing Luis Diaz and Harvey Elliott, back in the squad for the first time since September, came off the bench together shortly after Diogo Jota had headed in the opener early in the second half of Sunday’s tie at Anfield.
And they both made their mark on the match, with Diaz teeing up Takumi Minamino to double the Reds’ lead and Elliott then firing in a third.
Rubin Colwill later grabbed a consolation for Cardiff.
Thiago Alcantara also returned as a substitute on a satisfying afternoon for Jürgen Klopp’s side, who will host Norwich City in round five.
