The teenage midfielder has put pen-to-paper on a seven-year contract, with a club option of a further year. The move from his hometown club Rennes was confirmed this afternoon.

Mauricio has given his initial reaction to the signing.

‘Today is going to be his first training session with us. He is a young and talented player. We don’t know if we have the possibility for him to play tomorrow but we will assess him.

‘Now it is time to assess him until the end of the transfer window, and see if he is going to be with us or go on loan.’

Pochettino was also pressed on whether he is happy with the current state of his Blues squad, when he spoke at his pre-Borussia Dortmund press conference this afternoon.

‘I am happy with how the club is working, us included. We are working hard to try to finish the squad as soon as possible. But we all understand that maybe during the last few weeks of the transfer window, things are going to happen,' he said.

‘It is always better to have everything closed before. But not only for us, every other club too. It is important to close the squad in the way that we want.’