The Argentina international is now with Atletico Madrid and won the World Cup while a player with Atlanta United.
Arsenal had 56 positive reports on the midfielder, but ruled him out due to his physique.
Vidalle explained to ADN Deportes: "Thiago Almada, I've always insisted on him, I've always liked him, but he has a physical weakness, especially for the Premier League.
"I've done 56 reports on him because I've known him since he played in the eighth division, that is, in the U-15s."
Discussing how "deep" scouts go these days into following young players, Vidalle also revealed: “At the U20 World Cup in Argentina, two of my colleagues brought an eight or nine-page dossier on Declan Rice.
"It was so detailed it looked like an intelligence report. Age curves, mentality, how concentration changed during matches. That’s how deep we go now.”