Arsenal have reached an agreement in principle with Saint-Etienne to sign defender William Saliba, Sky Sports News understands.
The deal will see Saliba return to the Ligue 1 side on loan next season.
It is understood Tottenham had been in talks with the French side but never made a formal bid for the player.
The 18-year-old made 17 appearances for Saint-Etienne last season and was included in the French squad for the U20 World Cup during the summer.
Arsenal continue to work on deals for Real Madrid midfielder Dani Ceballos, who would join on a season-long loan, and Celtic left-back Kieran Tierney.
It is understood that the club are increasingly confident they can get both over the line.