Arsenal have agreed a deal in principle worth up to 38.5m euros (£32.67m) to sign Spain midfielder Mikel Merino from Real Sociedad.
The fee is an initial 33.5m euros (£28.43m), plus 5m euros (£4.24m) euros in add-ons.
Merino was part of the Spain team that won Euro 2024 and featured in all seven matches in the tournament, scoring a late winner against Germany in the quarter-final.
The 28-year-old has less than a year remaining on his contract at La Liga side Real Sociedad.
Merino would be Arsenal's third signing of the transfer window, after Italy defender Riccardo Calafiori and Spain goalkeeper David Raya, with the Gunners activating the option to permanently buy him from Brentford.