Enzo Robise admits Southampton's reputation for youth development convinced him about leaving France last year.
The 17 year-old left Reims to join Saints.
He told Foot Mercato: "I thought it was very flattering to be followed by a big club like Southampton, which has a very good reputation. It's really a good development club in England. They have trained great players.
"When I knew they were following me, I started to learn about them on the internet. I saw their infrastructure. It was on another level. Things connected themselves quite naturally afterwards.
"I had one year of training at Reims. When Southampton made me a proposal, I thought a lot about it. But when such a club comes, it's hard to say no. We know their reputation well, the players who came out of there. So it was obvious for me to say yes to their proposal and to sign there."