Son, a 33-year-old attacker, has announced that he will be leaving the club after Sunday's preseason friendly with Newcastle.
Frank has stated that the team has prepared for Son's exit and is confident in the abilities of other players to fill the gap.
He mentioned that Brennan Johnson has played on the left, while Wilson Odobert and Mathys Tel have also shown potential in that position.
Frank expressed his admiration for Son, calling him a "true Spurs legend" and one of the greatest players to have played in the Premier League.
Frank also noted that his arrival as manager may have helped to make the timing of Son's departure slightly easier, allowing the team to end on a high note.