The man, named by police only as Simon, has not been seen since 8pm yesterday, and officers today issued a picture of him as they appealed for help finding where he is.
Simon, age 29, was last seen leaving his home address in the Darnall area of the city.
He is white, 5ft 8ins tall and of slim build with fair hair. He is believed to be wearing a red and white baseball cap; black jacket and dark joggers. He has two rucksacks with him.
He is known to travel around the North West region by public transport and has links to the Manchester.
A police spokesman said: “Officers are becoming increasingly concerned for Simon's welfare and want to speak to anybody who has seen him.
Call 101 quoting incident number 27 of August 27.