The 17-year-old, who broke through in the first team this season, picked up the knock during England Under-20 duty.
Per The Mail, Newcastle are waiting for the results from a scan before they decide how to proceed.
Advertisement
Advertisement
Miley has been key for manager Eddie Howe in recent months, but the club do not want to risk his long-term health.
He has starred in their past 17 league matches, starting 14 of them and coming off the bench three times.
Miley's England Under-20 side beat Czech Republic's youngsters 3-1 in the Elite European League.