David Moyes will instead prioritise a striker, a centre back and Jesse Lingard making do with his existing crop of keepers.
Johnstone was valued by West Brom at £20m but the money will be better invested elsewhere.
36-year-old Łukasz Fabianksi remains one of the best keepers at premier league level and there was never any urgency for a keeper given that he is keeping them all at bay.
He has signed another 12-month extension with West Ham but looks likely to have another two years left in him at the highest level.
And his deputy Darren Randolph has a contract until 2023 and has proved he is more than capable in the Premier League.
The Hammers also retained 35-year-old David Martin for his experience in helping the young goalkeepers get up to speed.
It is hoped that either 22-year-old Nathan Trott or 22-year-old Joseph Anang can progress to the senior team over the next two years.