The Reds have long since been the leading contenders to sign Brighton’s World Cup-winning playmaker, with negotiations having been ongoing for several weeks.
Brighton resisted initial interest in Mac Allister in January after his impressive mid-season exploits with Argentina in Qatar, though both he and midfield colleague Moises Caicedo - wanted by both Arsenal and Chelsea - were always expected to move on this summer.
Transfer specialist Fabrizio Romano reported on Monday that Liverpool had reached a full agreement over making the 24-year-old their first signing of what is expected to be a busy transfer window on Merseyside.
They are said to have triggered a complex buyout clause in Mac Allister’s Brighton contract reportedly worth far less than the £60million often reported, with the player having agreed a five-year contract that runs until 2028 as he prepares to undergo a medical in the next couple of days.
Mac Allister is far from the only midfield target in Jurgen Klopp’s sights this summer, with Romano adding that talks have also already been held with the respective agents of Nice’s Khephren Thuram and Manu Kone of Borussia Monchengladbach, also on Chelsea’s radar, with Celta Vigo starlet Gabri Veiga also of interest.
Liverpool’s need for a midfield overhaul has been apparent for some time, exacerbated by a hugely disappointing season in which they went from title contenders to not even making the Premier League’s top four despite a late charge.
The Reds ended up finishing a distant fifth behind Manchester United and Newcastle, missing out on the Champions League for the first time in seven seasons as they had to make do with qualification for the Europa League instead.
But Klopp is confident that Liverpool remain an attractive proposition for prospective new signings despite the lack of Champions League football on offer next term.
In terms of midfield exits, Naby Keita, James Milner and Alex Oxlade-Chamberlain are all leaving the club after the expiration of their respective contracts, along with forward Roberto Firmino, while Arthur Melo will return to parent club Juventus this summer after an injury-ravaged season-long loan.