South Korean international Son sustained the injury during his country’s 3-2 defeat to Qatar and had to be substituted during the 24th minute.
Son netted 21 goals from 47 games this past season and Spurs have confirmed that scans have revealed a fracture of his forearm.
Mauricio Pochettino’s team will begin their pre-season against Paris-Saint Germain on July 23 and participate in the International Champions Cup against the likes of Roma and Manchester City.
After missing out on the Premier League title for a second successive season, Spurs will be looking to challenge for major trophies next season.
