The incident happened in the Spencer Road area of the city.
There has been widespread shock following reports that a local businessman has been assaulted in Spencer Road area of Derry.
The PSNI are investigating the assault following the Apprentice Boys of Derry parade on Saturday evening.
It is believed a bandsman from outside the city was involved in the incident.
A spokesperson for the PSNI said: "Police received a report of an assault in the Spencer Road area of Derry shortly before 6pm yesterday, Saturday, August 12. Enquiries are ongoing and anyone who witnessed the incident is asked to contact police on 101 quoting reference 1295 of 12/08/23."
SDLP Foyle MLA Sinéad McLaughlin said the "brutal assault" is deeply shocking.
"There is no cause for such a totally unacceptable and violent act and to think of his children seeing him in this condition is just awful.
"I wish the victim of this attack a full and speedy recovery and encourage anyone with any information to come forward and assist the PSNI with its enquiries," she said.
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