Thomas Partey has completed and passed his Arsenal medical and arrived in London to finalise a high-profile deadline day transfer ahead of the 11pm BST international cut-off, Standard Sport understands.
The Gunners launched a late effort to sign their top midfield target earlier on Monday, notifying LaLiga of their intention to pay the Ghanaian international's £45million release clause at Atletico Madrid.
Personal terms had already been agreed between Arsenal and Partey's representatives, with the player undergoing a medical in Madrid before travelling to London this evening.
Partey is Mikel Arteta's number one transfer target as the Spaniard seeks to bolster his midfield options at the Emirates.
Arsenal have already signed winger Willian, centre-back Gabriel and goalkeeper Runar Alex Runarsson this summer in addition to wrapping up permanent deals for loanees Pablo Mari and Cedric Soares, while Houssem Aouar was key another target before deciding to remain at Lyon.
Atletico did not want to lose Partey, but the existence of that £45m release clause and the player's desire to make the move to north London rendered them powerless to prevent his exit.
Los Rojiblancos are expected to announce the arrival of Lucas Torreira on loan from Arsenal on Monday night and Diego Simeone will hope that the Uruguayan can help fill the void left by Partey's departure.
Arsenal also sanctioned the exit of another central midfielder on deadline day, with Matteo Guendouzi - who has not played for the club since June - joining Hertha Berlin on loan for the rest of the 2020-21 campaign.
