The 23-year-old full-back has insisted he has always dreamed of playing for the Three Lions and rejected suggestions his reason for withdrawing was not serious enough
It had been suggested that the Chelsea defender left the Three Lions camp with minor illness, but the 23-year-old took to Twitter to insist his condition is far more severe.
"Just to clarify.... Its not a "sore throat" Im ill. Swollen glands in my neck... And constant headache for 3 days now and freezin cold," Bertrand tweeted.
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"Do you think a "sorethroat" could stop me being apart of a match for my club or country #yourf***ingnuts this is what every boy dreams of."
Bertrand has enjoyed a breakthrough year at senior level, appearing in last season's Champions League final.
He went on to represent Team GB at the Olympic Games before earning his first England cap in a friendly against Italy back in August.
His tweets regarding the matter have since been deleted.