The injury Jordan Henderson suffered in Wednesday's win over Newcastle United prompted Jurgen Klopp to make a late swoop for a midfielder, with Alex Oxlade-Chamberlain, Thiago Alcantara and Naby Keita also sidelined.
Out of the blue on transfer deadline day, reports emerged of Liverpool agreeing a deal to sign Arthur on loan from Juventus, and the Brazil international is now believed to be on Merseyside as he finalises his move.
According to journalist Fabrizio Romano, Arthur has now passed his medical and signed his deal as a Liverpool player, and the Reds are now preparing to announce the 26-year-old's arrival.
Arthur will join the Premier League giants, and there is no option nor an obligation to make the deal permanent at the end of the current season.
The former Barcelona man is yet to make an appearance for Juventus under Massimiliano Allegri this season and has totalled just one goal and one assist in 63 outings for the Old Lady since his arrival in 2020, which saw Miralem Pjanic head in the other direction.
Arthur will become Liverpool's fourth signing of the summer window, following Darwin Nunez, Calvin Ramsay and Fabio Carvalho to Anfield.