The 24-year-old, from Macclesfield, was allegedly punched on Seasiders Way after Macclesfield Town beat Blackpool on penalties in the Carabao Cup match. The loss meant the Seasiders exited the competition.
A Lancashire Police spokesman said an investigation has been launched and no one has been arrested yet.
A spokesman said: "We are investigating after an assault in Blackpool. The victim, a 24 year old man from Macclesfield, was allegedly punched on Seasiders Way in the town on Tuesday night. He was taken to hospital suffering from a suspected fractured jaw.
"An investigation is in its early stages and anyone with information should call 101 quoting log number 0218 of August 14th or independent charity Crimestoppers on 0800 555 111."