Arsenal are close to sealing the club-record signing of Mesut Ozil.
Real Madrid's attacking midfielder has completed part of his medical and is expected to be announced as an Arsenal player before the transfer window closes at 11pm.
Real will receive £42.5m for the 24-year-old if the deal goes through - almost three times the reported amount Arsenal paid Zenit St Petersburg for their current record signing, Andrey Arshavin.
And Germany international Ozil, who joined Real in 2010 from Werder Bremen for 15m euros, is set to become the first through the Bernabeu exit door following the world record-breaking arrival of Gareth Bale from Tottenham.
Gunners boss Arsene Wenger said in the aftermath of Sunday's 1-0 victory over Spurs: "It is a little bit like a domino game. Maybe something will happen in the last 24 hours, maybe not. It is very difficult to predict, but maybe we can surprise you."
Ozil may not be the only high-profle player arriving at The Emirates before the 11pm deadline - an interest has been registered in Chelsea striker Demba Ba.
Arsenal are understood to have offered a £1.5m loan fee for Ba, while Chelsea want double that amount and are happy to keep the player if a move does not materialise.
Palermo goalkeeper Emiliano Viviano, meanwhile, has joined on an initial season-long loan as cover for Wojciech Szczesny.
Arsenal will then have an option to buy the Italy international next summer.