Boca Juniors president Daniel Angelici has confirmed the club has agreed the sale of Leonardo Balerdi to Borussia Dortmund.
The 19-year-old has only made five league appearances for the beaten Copa Libertadores finalists, but is regarded as a top prospect.
Reports in Argentina have indicated Dortmund agreed to pay €15 million (£13m/$17m) for the defender, with a further €2m potentially due to Boca in add-ons.
And Angelici suggested the deal could go through in a matter of days, with Balerdi departing after fellow defender Lisandro Magallan joined Ajax earlier this month.
"We have reached an agreement and this is always subject to a medical check. It has a lot of conditions.
"In that regard, I think we ended up making a very good fee for a player, but we wished he'd played in Boca's first team for a while."