Nottingham Forest submitted a £40m bid for the 19-year-old England Under-19 international, sparking immediate outrage among Everton fans who viewed him as a vital homegrown prospect.
Supporters made their anger clear by chanting Armstrong's name throughout a draw against Bournemouth and warning of severe unrest if the deal went through.
Following discussions led by club owner Dan Friedkin, the Everton board ultimately decided to reject the approach and keep the player at Goodison Park.
Manager David Moyes admitted he understood the fans' frustration and will retain a young talent seen as a key part of the club's future.
