The 35-year-old was six over when he had to withdraw because of a problem with his foot.
It is understood Hoey has had callouses on his feet for a while and that is what caused the issue on Friday.
"Massively disappointed to have retired from @The_Open during today's round. Massive gouge out of my foot & can't walk," Hoey tweeted after pulling out.
Hoey does not yet know whether he will be fit enough to defend his Russian Open title next week.
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