Former mentor backs Argentine prodigy
Demichelis is adamant that his former River Plate pupil Mastantuono possesses the personality, physicality and technical ability to thrive with Los Blancos despite his temporary switch to La Viola. The tactician handed the midfielder his senior bow aged 16 in January 2024 before Madrid completed a €45 million transfer in August 2025. Now 19, the youngster moved to Italy this term in search of regular first-team football.
European adaptation requires patient approach
Having become the youngest player in history to feature in an official match for Argentina's senior national team at 17, the playmaker made his Santiago Bernabeu debut on August 20, 2025 as a 68th-minute substitute for Brahim Diaz against Osasuna. Although he arrived as the most expensive signing in Argentine football history on a six-year deal running until June 2031, adjusting to European football's elite level demands patience.
Highlighting the need for time while recalling the build-up to the teenager's professional breakthrough during a virtual media roundtable on Monday, Demichelis, as quoted by ESPN Argentina, said: "He needs time. You have to look back at how many South American players have joined top European clubs and gone on to succeed. Santiago Solari or Gonzalo Higuain needed time to adapt to one of the biggest institutions in the world, if not the biggest. Especially when you are that young.
"Franco didn't make his debut at 16 by magic. There's a wonderful backstory before he did. I spoke with him, with River's directors, and with his parents to see if they were prepared for what was coming, and also to understand his contract situation. Physically, he was among the top three to five players day in and day out, particularly in recovery; on top of that, he had the personality and temperament to rise to the occasion. I believe Xabi Alonso (at Real Madrid) noted his personality when he first met him."
Record release clause foresaw greatness
After watching the youngster net his maiden senior goal for the Millonario in a 1-0 win over Sarmiento in July 2024, Demichelis even urged club directors to set his release clause higher than the fee agreed for a fellow academy graduate's move to England.
Detailing how he pushed the board to demand a record figure while backing the player's current spell in Serie A, Demichelis added: "The board took note of his situation. At that point, we had sold Claudio Echeverri to Manchester City, and they thought about setting his buyout clause at the same value. But I said no - Franco was going to be a player for Real Madrid. From there, the club did fantastic work with his agent; they set a buyout clause that was unheard of for Argentine football, and it ended up being the biggest sale in the country's history.
"I don't doubt his abilities or his personality. Real Madrid waits for no one. He has decided to go get playing time (in Italy) for now, but I have zero doubt that he is a player built for that club, both in personality and in physical and technical quality."
Impressive Florence start builds momentum
That decision to spend the 2026-27 campaign in Florence is already paying dividends, with Mastantuono scoring three goals across his opening seven Serie A outings. Building on that productive start in Italy's top flight will be vital as he prepares to fight for a starting berth back in the Spanish capital next summer. Meanwhile, Demichelis is preparing his RB Leipzig side to face Madrid in the Champions League this week.