And in his first game back for the Toffees last night against Werder Bremen he was taken off after 61 minutes after falling awkwardly - the worry being that he had damaged the same foot again.
Cahill had an X-ray earlier on Wednesday before Everton announced on their website, that he was being referred to a specialist.
Everton's assistant manager Alan Irvine was considered with his view on Cahill after the 2-2 draw with the Germans.
He said: "He felt his foot again which obviously is a bit of a worry. He landed on it awkwardly which probably frightened him a little."