The highly-rated 18-year old full-back is attracting plenty of interest from Chelsea but Pochettino says he is happy at St Mary's and will continue his development on the south coast for the time being.
"It is a very clear situation. The player wants to stay, the club is not willing to sell," Pochettino said.
"What we also need to consider is that he is an 18-year-old player, that he is still maturing, still progressing. He is still learning how to be an experienced player.
"We need to be very calm about the situation. It has taken him some time to mature as a player and I think all these rumours and all this speculation around him is not beneficial for him. I think it is negative for him."
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