England inflicts rare defeat on Belgium
The pair withdrew from the squad on Tuesday, reducing Gareth Southgate's pool of available players to 28.
Chelsea full-back Chilwell, who was absent for the opening two fixtures of the international break after breaching COVID-19 restrictions, is thought to be suffering from a foot injury.
Atletico Madrid defender Trippier's reason for withdrawing is reportedly personal.
England recorded an impressive 2-1 win over Belgium at Wembley on Monday (AEDT), when Trippier played the full match.