Southampton have signed midfielder Carlos Alcaraz from Racing Club, says the Argentine club.
Racing, who play in the top division of Argentine football, say Southampton have paid £13.65m euros (£12m) for the 20-year-old.
In a post on social media, they added that there is a 15% sell-on fee if the south coast club sell Alcaraz.
Southampton are bottom of the Premier League after six defeats in a row and face rivals Everton on Saturday.
Nathan Jones' side did beat Crystal Palace in the FA Cup on Saturday and host Manchester City in the Carabao Cup on Wednesday.