Williams, an 18-year-old Wales U19 international, is expected to start at right-back for the Carabao Cup fourth-round tie against Arsenal at Anfield.
The teenager has been a regular this season for the U23s side and the U19 team in the UEFA Youth League, scoring in the 4-2 win against RB Salzburg earlier this month.
Williams has spent time training at Melwood in recent weeks, with Jürgen Klopp having been impressed by the young defender.
And with Ki-Jana Hoever on international duty with Holland at the U17 World Cup, the Welshman is now in line for a starting role.