Ancelotti wished Casemiro well, saying the club cannot stop the player’s wish.
There have been rumours that the former Real Madrid man wants to leave this summer, less than a year after returning to the club from Juventus.
Ten Haag had agreed to give the squad a break for the remainder of the weekend but changed his mind after the humiliating loss.
Manchester United suffered a second loss of the season on Saturday evening after falling to Brentford 4-0 at the Gtech Community Stadium.
Eriksen, 30, spent half of last season on loan at Brentford, making four assists and scoring one goal in 11 games.
He is set to make a first competitive appearance since suffering a cardiac arrest on the pitch at Euro 2020 in June last year.
The win moved Liverpool to 51 points from 23 games, with leaders Manchester City having played one game more.
Liverpool are now second on the EPL log with 45 points in 21 games, displacing Chelsea who had 43 points in 22 games so far.
Clubs will continue to conduct daily lateral flow tests (LFTs) on training days, but PCR tests will only be taken to confirm a positive lateral flow result.
A lone strike by defender Ben Chilwell saw Chelsea keep their grip atop the English Premier League despite Brentford’s late game push.
