Son sustained a fractured eye socket playing for Tottenham Hotspur against Marseille in the UEFA Champions League last month but declared on social media last week that he would be available for selection for the Finals.
"We are in contact with him, with the Tottenham medical department but about the exact time, the exact day he can train with the team we don't have that information yet," Bento said after naming his selection in Seoul on Saturday.
"So we need to wait, we need to analyse day-by-day his situation. We have time to decide and the most important is he recovers as well as possible he feels comfortable and then we will take the final decision."