The Brazilian – who is currently away representing the Selecao at the Copa America in Chile – has emerged as one of the stars of Ligue 1 since his 2013 Stade Louis II debut.
Fabinho has been a key member of Monaco’s side through their return to the top tier of French football, and also played a part in their Champions League adventure last term – in which they knocked out Arsenal at the last 16 stage.
His performances appear to have alerted Louis van Gaal, who is ready to pay up to £10.2m for the full-back, as he plots to bolster his options on the right side of his backline.
Fabinho – who has two Brazil caps and stands at 6ft. 2” – would be an upgrade on Antonio Valencia, who spent much of last season in the position despite being a wide attacker.