The Press Association understands the breach relates to an unauthorised absence from training.

The 31-year-old also missed Saturday’s 2-0 loss to Arsenal, but that was put down to illness.

Grealish, who is on a second consecutive season-long loan from Manchester City, had started Everton’s previous three Premier League matches against Ipswich, Hull and Chelsea, and has made a total of six appearances for the Toffees this term.

Everton are hosting Newcastle for a place in the quarter-finals, where Fleetwood await after their shock victory over Premier League champions Arsenal on Tuesday night.