July 16 (Reuters) - Manchester United have reached a deal with Eredivisie champions Ajax Amsterdam to sign Argentine central defender Lisandro Martinez for 45 million pounds ($53 million), the BBC reported on Saturday.

The report added that Martinez has flown to Manchester to undergo a medical prior to his move.

The 24-year-old, who can also play in midfield, would be manager Erik ten Hag's third signing following the arrivals of Dutch left back Tyrell Malacia and Denmark midfielder Christian Eriksen.

He was a key figure for Ajax last season, making 36 appearances in all competitions and helping them to the league title and a runners-up finish in the Dutch Cup.

Ten Hag managed Martinez for three seasons at Ajax after the player moved to the Netherlands from Argentine side Defensa y Justicia in May 2019. Martinez made 118 appearances in all for the Dutch club.

Capped seven times by Argentina, he would bolster United's defence, which conceded 57 goals last term - the most among the top six.

He could also give the manager an extra option in midfield after the departures of Paul Pogba and Nemanja Matic.

United, currently on their pre-season tour in Australia, finished sixth last season. They open the new campaign at home to Brighton & Hove Albion on Aug. 7. ($1 = 0.8437 pounds) (Reporting by Dhruv Munjal in Bengaluru, additional reporting by Aadi Nair; Editing by Hugh Lawson)