Adam Lallana will not feature for England against Spain or Switzerland because of a groin strain.
The attacking midfielder, who was not included in the squad for the World Cup that progressed to the semi-finals, has suffered a problem that requires further assessment.
He will return to club side Liverpool, missing out on England's UEFA Nations League opener with Spain and a subsequent friendly with Switzerland.
Lallana has played just three minutes of Liverpool's four opening Premier League matches. The Reds are top on goal difference with a perfect record.