Saliba (left) joined Saint-Etienne in 2016
Arsenal are set to sign Saint-Etienne defender William Saliba in a 30m euro (£27m) deal that will see him loaned back to the Ligue 1 club next season.
The Gunners will pay for the 18-year-old in instalments, which will not have a major impact on their restricted budget of around £45m for this summer.
Saliba is one of the game's most highly rated young centre-backs.
Arsenal remain in the market for a player to come straight into the first-team squad in the same position.
Saliba joined Saint-Etienne in 2016 and no announcement on Arsenal's acquisition of the France Under-20 defender is expected for several days while the transfer is finalised.
Arsenal are also pursuing Celtic left-back Kieran Tierney, 22, and additionally hope to recruit a central midfielder and winger.
Meanwhile, former Arsenal midfielder Edu will be confirmed as the club's first technical director imminently.
Edu, 41, played for Arsenal between 2001 and 2005, winning the Premier League twice and FA Cup twice.