The Reds are through to the quarter-finals despite Jurgen Klopp heavily rotating his squad
Memories of Sunday’s 5-0 destruction of Manchester United were fresh in the minds of the travelling Liverpool support but there were few traces on the pitch as Jurgen Klopp changed all 11 players and got a radically different display as a result.
When Minamino turned in Neco Williams’ cross in the 62nd minute, it was Liverpool’s first shot on target after Preston had brought a number of saves out of Adrian in the first half.
Origi flicked in a second six minutes from time, but the gap between Klopp’s ruthless stars and their more modest back-ups was obvious as Liverpool only occasionally bared their teeth against a side 19th in the Championship and sporting several changes of their own.
Preston had never reached the quarter-finals, but that carrot was not enough to prevent Frankie McAvoy from swapping nine of the players who started the weekend’s 2-0 defeat to Blackpool – with on-loan Sepp Van Den Berg one of two survivors having received permission to face his parent club.
Klopp handed a debut to teenager Harvey Blair while Tyler Morton got his first start but there was also plenty of experience as Joel Matip returned to partner Joe Gomez in defence.
It was no surprise to see Liverpool boss possession – goalkeeper Declan Rudd was the only Preston player to touch the ball in the opening five minutes – but they could not translate that into chances as the hosts defended strongly.
Instead it was Preston who threatened. Tom Barkhuizen cut inside Matip before firing over, then Ryan Ledson tried an ambitious volley from the edge of the area which sailed over.
Brad Potts was the next to escape Matip but his rising shot was pushed over by Adrian.
The best chance came in the 28th minute. After Gomez squandered possession Ali McCann put it on a plate for Sean Maguire, only to see Adrian make a superb point-blank save. The ball fell invitingly for Ledson, but his shot struck Williams in the face on the line before Potts blazed over.
Liverpool somehow escaped, but they went in at the break still yet to test Rudd despite having 79 per cent possession.
Matip was replaced by Nat Phillips at the break, and Liverpool were quickly on the front foot, with Minamino going close before Alex Oxlade-Chamberlain twisted to make space before unleashing a powerful shot which sailed narrowly wide.
A largely frustrating night for Blair came to an end moments later as Conor Bradley replaced the former Manchester United prospect, but Morton continued to impress, and almost found Minamino with a curling cross from deep.
They broke the deadlock with their first shot on target just after the hour. Williams, pushed forward by Bradley’s arrival, pulled the ball back for Minamino to flick it beyond the reach of Rudd and score his fifth Carabao Cup goal in as many appearances.
Preston seemed to sense their chance had gone as heads dropped, and Origi soon confirmed their fears as he scored his customary Carabao Cup goal – making it 11 in his 10 starts in the competition.
When Kostas Tsimikas’ cross from deep struck the crossbar it bounced down for Williams. His shot was blocked but the ball sat up for Origi to flick in with an acrobatic twist of his leg.
Minamino should have added a third when he raced through on goal moments later, denied by Rudd, but further goals would have been harsh on Preston.