The huge Old Trafford clash is kicking off at 15:30 GMT and will be shown live in the UK on ITV1, as the Reds look to reach Wembley by knocking our old foes out.
The tie is reward for our 1-0 victory at Nottingham Forest in midweek, courtesy of Casemiro's late header from a Bruno Fernandes free-kick.
This fixture being added to the schedule means our Premier League home clash with Sheffield United must be rearranged.
We have a good record against the Merseysiders in the competition, including beating them in the final in 1977 and 1996, with 2-1 and 1-0 triumphs.