Chilwell, who won his first cap in last month's friendly win over Switzerland, had been included in the Under-21 squad.
Shaw reported on Monday with the rest of Gareth Southgate’s squad but has now returned to Manchester United for treatment.
England, who are second in Nations League Group 4, face third-placed Croatia in Rijeka on Friday before taking on leaders Spain in Seville the following Monday.
(Writing by Ken Ferris; Editing by Pritha Sarkar)
