Key Points

Mastantuono is set to arrive at the Bernabeu in August after Madrid triggered his buyout clause of 63 million euros (around 72 million US dollars).

The 17-year-old revealed that a phone call with Alonso, who replaced Carlo Ancelotti as Real Madrid's manager last month, had immediately convinced him it was the right move.

"The way Xabi handled things with me was incredible. I'm really grateful," Mastantuono said in an interview with DAZN, reports Xinhua.

"That conversation had a big impact on me. When a coach genuinely wants you, that's a huge show of trust, especially when you're leaving a club as massive as River. That's not an easy decision, but his words gave me the motivation I needed to make the leap."

Mastantuono has enjoyed a breakout season for River Plate with seven goals and four assists in 21 games across all competitions.

His performances earned him a call-up to Argentina's national team, and he became the youngest player to appear in an official match for the Albiceleste when he featured in a World Cup qualifier against Chile earlier this month.

Despite attracting interest from several top European clubs - including newly crowned Champions League winners Paris Saint-Germain - Mastantuono said Real Madrid's offer was too good to refuse.

"It's the team that has won the most in Europe, any player wants to play there, and the fact that it's happening to me is a dream come true," he said.

Mastantuono pointed out that his current focus is on helping River Plate at the FIFA Club World Cup in the United States, but he is already looking forward to the new challenge.

"I know I still have a lot to learn in football and I'm eager to keep growing," he said. "I like to listen, observe and absorb everything around me. That's my greatest strength and it helps me make decisions on the pitch."

- IANS