William Saliba's £27m transfer to Arsenal was officially confirmed on Thursday afternoon following weeks of speculation.
Although, fans won't see him in the club's colours immediately.
Instead they'll have to tune into Ligue 1 action in order to keep up with the teenager's progress in the upcoming season and Saliba has been loaned back to Saint-Etienne to continue his development.
The 18-year-old sat down with Arsenal.com to explain why he won't be linking up with his parent club until next summer.
"Well, it was important first of all because I wanted to prove myself for another year at Saint-Etienne, before I come to try and establish myself here at Arsenal," he said. "This is a big club, and when you come here, you need to be ready.
"So I'm going to try and have a great season with the club that developed me in order to be ready for Arsenal."
Not too long after Saliba's move to the Emirates Stadium was made official his agent posted a video montage of their few days in London this week.
It was very much a behind the scenes view.
And some Arsenal fans spotted the moment where Saliba is signing his contract and Head of Football Raul Sanllehi appears to have a little dance.
Take a look at some of the responses on Twitter...
