Championship club Leeds have signed Ideguchi from Japanese outfit Gamba Osaka in the January transfer window.
The 21-year-old central midfielder has arrived at Elland Road with a strong reputation, having already played 11 times for the Japan national football team.
The talented and promising young midfielder has been loaned out to Spanish second division side Cultural Leonesa for the rest of the season.
Former Leeds winger and manager Gray hopes that Ideguchi has the same impact at Elland Road that Son has had at Spurs.
Son joined Tottenham from German club Bayer Leverkusen in the summer of 2015 for a transfer fee reported by The Guardian to be worth £22 million.
The 25-year-old South Korea international, who can operate as a winger or as a forward, has established himself as a key figure for Spurs.
Gray told LUTV about Ideguchi: “You never know with players like that. You are looking at the boy from Asia, he is playing for Tottenham Hotspur, Son. Tremendous player. A fixture in their side. If you get a player like that, it could be anything."