Manchester United confirmed on Sunday afternoon that an agreement has been made with Ajax for the transfer of centre-back Lisandro Martinez.
The 24-year-old centre-back spent three seasons at Ajax since moving to the Amsterdam club in 2019, and is now set to reunite with his former manager Erik ten Hag at Old Trafford.
Martinez arrives as United's third summer signing, after Christian Eriksen and Tyrell Malacia joined the squad earlier this month.
"Manchester United is delighted to announce the club has reached agreement with Ajax for the transfer of Argentine international defender Lisandro Martinez, subject to medical, to player terms being finalised, and to UK visa requirements," a statement read.
Martinez flew into England over the weekend to complete his deal, which is expected to be a five-year contract.
Centre-back Martinez will depart Ajax for an initial£48.3m but it could rise by a further £8m, the Dutch club confirmed in a statement.
The 24-year-old moved made 120 appearances for Ajax, scoring on six occasions.
Martinez worked with Ten Hag throughout his time at the Johan Cruyff Arena and will link up with him again in Manchester.
United are currently out in Australia for their pre-season tour and have two more friendly fixtures before they conclude their time Down Under.
The Red Devils will face Crystal Palace on Tuesday and another Premier League side next weekend in Aston Villa.
Fellow new addition Eriksen will not be flying out to Australia, and it could also be a similar case for Martinez, who will join fellow Argentinian Alejandro Garnacho at Old Trafford.