Tottenham are challenging north London rivals Arsenal for Saint-Etienne defender William Saliba.
The Gunners were set to secure a 30m euro (£27m) deal for the 18-year-old that was to see him loaned back to the Ligue 1 club next season.
The deal was in instalments and would not have had a big impact on Arsenal’s restricted £45m summer budget.
But Spurs, who signed Tanguy Ndombele for a club record £53.8m this summer, have submitted a late bid.
Saliba, a France Under-20 international, joined Saint-Etienne in 2016 and is one of the game’s most highly-rated young centre-backs.
Arsenal remain in the market for a player to come straight into their first-team squad in the same position.
Arsenal are also pursuing Celtic left-back Kieran Tierney, 22, and 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.