Arne Slot demanded a higher level of quality from his rotation players after a 1-0 horror show at Plymouth banished their Quadruple hopes.
The Liverpool manager insisted his players worked hard enough but he was disappointed with his side's final product against the Football League's worst defence.
Plymouth claimed a historic win at Home Park thanks to Ryan Hardie's second-half penalty after Harvey Elliott was pulled up for handball.
It was only the fourth time that lower-league opposition have knocked the Premier League leaders out of the FA Cup.