The actress, who plays Rovers Return landlady Stella Price, told Twitter followers that she fell recently but tried to ignore the pain.
Collins wrote: "Pulling pints in Rovers with fractured shoulder very difficult I can tell you !!! (sic)"
She later elaborated in response to a fan, saying: "I fell a few weeks ago and ignored the pain went to gym etc but got worse had a scan got hairline fracture !! Can't do much."
Collins's character is to team up with Sunita Alahan to get revenge on love rat Karl Munro in coming weeks.
She also confirmed that Stella will find love with a new man following her split from Karl earlier this year.
> 'Coronation Street': Stella Price's new boyfriend revealed?
> 'Coronation Street' Michelle Collins reveals Elsie Tanner inspiration
> Michelle Collins: 'Psychics stopped me quitting Corrie' Get the Inside Soap magazine on your iPhone or iPad