Southampton have agreed a fee of £25 million including add-ons for Arsenal goalkeeper Aaron Ramsdale, sources told ESPN.
The 26-year-old is expected to undergo a medical on Thursday and finalise personal terms.
Sources added that the fee consists of an initial £18 million with a further £1 million due if Saints avoid relegation from the Premier League and the remaining £6 million based on individual performance targets.
The Gunners are expected to move for Espanyol goalkeeper Joan García as Ramsdale's replacement, although sources have told ESPN the LaLiga club will demand a fee in excess of €20 million.
Ramsdale fell out of favour at Arsenal after the club moved to sign David Raya from Brentford last summer, initially on loan for £3 million before making the deal permanent in July for a further £27 million.
Bournemouth showed an interest in Ramsdale but opted to sign Kepa Arrizabalaga on loan from Chelsea while Southampton were close to signing Justin Bijlow until the Feyenoord goalkeeper failed a medical.