Brizuela scouted Mastantuono as a junior player for River Plate and has followed his career closely.
Knowing the young midfielder has struggled in is first year with Real Madrid, Brizuela is urging patience.
He told AS: “There’s too much haste to accelerate the timeline, but no one should despair. It’s very important to follow the proper procedures. Franco was just starting to take off at River when he was signed by Real Madrid, he went to Europe, and the uprooting is a significant factor.
"It would have been a good decision to let him mature here for another year or even two because bringing him so soon could make the final journey longer. It’s the same case as (Claudio) Echeverri. Both are pure elite and will play for the Argentine national team for many years.
"Proper planning is necessary for their development to be consistent. Franco is a sensational, top-tier player, very intelligent, and with a tremendous personality.
"In the future, he will be the player Real Madrid bought and will live up to expectations. I have no doubt about that, but it’s something that takes time and requires patience ,”