West Ham are prepared to let Adrian leave despite Darren Randolph imminent move to Middlesbrough.
After signing Joe Hart on loan from Manchester City for the season ahead the Hammers are set to clear out both their senior goalkeepers.
Randolph has agreed a £4.5million move to Boro where he has a deal worth £27,000 a week.
The Republic of Ireland international impressed enough at the London Stadium to start 22 Premier League games last season but would not be considered to play ahead of Hart.