River Plate insist Real Madrid must pay Mastantuono buyout clause

Real have let River know they're keen on the 16 year-old midfielder, with negotiations already underway with the player's management team.

Those inside Real's management team are convinced by Mastantuono's potential and future prospects, but River are reluctant to sell the teen.

Instead, says AS, Real face the need to pay €41.5m to secure the youngster.

However, even if they pay Mastantuono's clause, they'll still face an eighteen month wait to be clear to bring the teen to Spain.