The Frenchman has become a Red Devils target, with reports suggesting that a £15 million fee has been agreed with Juve.
Rabiot has now seemingly hinted that a transfer is set to take place, addressing Juventus in a post from a fan:
"Thank you, bye."
Erik ten Hag's side are in stark need of midfield reinforcements having encountered a woeful start to the Premier League campaign.
United have lost their opening two fixtures, slumping to a 2-1 defeat to Brighton & Hove Albion and getting thrashed 4-0 by Brentford.
The performances of midfield duo Scott McTominay and Fred have been criticized, with the former having been dropped following the defeat to Brighton.
Juventus kick off their Serie A campaign on Monday night, August 15 against Sassuolo at the Allianz Stadium.
Rabiot is suspended for the game so will play no part in what could have been his farewell match for the Old Lady.
The midfielder made 45 appearances for Juve last season and has earned 29 international caps for France.
He is likely to come straight into United's side should he arrive, with Ten Hag eager to make alterations to his team.
The Dutch tactician spoke following United's horrific 4-0 loss to Brentford, saying:
"We need new players and quality players. We will try and convince them to join."
A new-look midfield for Manchester United
Manchester United have still not given up their pursuit of Barcelona midfielder Frenkie de Jong.
The long-running transfer saga is still ongoing and the latest development comes as De Jong has admitted to teammates that he may join the Red Devils, as per SPORT.
The Dutch star has previously played under Ten Hag at Ajax, with the duo winning two Eredivisie titles together.
De Jong may arrive alongside Rabiot at a crucial time for Ten Hag, who is starting to feel the pressure following two shock defeats.
The Red Devils next face arch rivals Liverpool at home.
A third consecutive defeat for United would only add more turmoil to what is a tumultuous situation at Old Trafford.
There are still question marks over the future of star man Cristiano Ronaldo, who appears to want to leave the club.
Ten Hag has had to deal with the Portuguese star's situation alongside a lack of additions in what has been a difficult start for the Manchester United manager. The Red Devils have only signed left-back Tyrell Malacia, midfielder Christian Eriksen and centre-back Lisandro Martinez thus far.