Liverpool goalkeeper Caoimhin Kelleher is set to move to Brentford after the clubs agreed a £12.5m fee for the player, rising to £18m in add-ons.
The Republic of Ireland international, 26, is seen as a replacement for the Bees' number one Mark Flekken, who is heading to German side Bayer Leverkusen.
The Bundesliga club have agreed a fee of about £8m for the 31-year-old Dutchman.
Kelleher has a year left on his contract at Anfield but Valencia keeper Giorgi Mamardashvili will join the Premier League champions in July to compete for the number one shirt with established first choice Alisson Becker.