The lively winger will travel to the UAE after the game in order to link up with his South Korea teammates, who are currently competing in the Asian Cup.
Son could miss as many as five games for Spurs and he wants to make sure he gets an important win over United in his last appearance.
"It's not easy for me to leave the team at this important time," Son told Sky Sports.
"I feel very sad and sorry but I want to win this game and go with confidence to Dubai.
"To play for your country is always a proud moment, but it's tough for me having missed one month of the season already.
"I want to go with three points, with confidence to Dubai."