Davies faces between three and four months out of action after the defender underwent surgery yesterday (Thursday) to rectify a knee problem that flared up during last Saturday's win over Walsall.
The injury is believed to be linked to an old issue that has troubled Davies in the past.
This devastating piece of news for both the defender and City means Bantams boss Phil Parkinson will most likely be without Davies' services until into the new calendar year.
With Davies sidelined for the foreseeable future, Parkinson now has a genuine dilemma on his hands when it comes to filling City's two centre half positions for the Tranmere fixture.
Both Rory McArdle and Carl McHugh are unavailable to the City chief due to international duty, while Matt Taylor is currently on loan to League 1 rivals Colchester Untied and cannot be recalled due to the terms of the loan agreement.
All of this means that City are left with Luke Oliver - a defender who has only started two games in the last year due to a long-standing Achilles problem - as the club's only fit and available centre half to choose from for Sunday.
Look out for Phil Parkinson's reaction to Davies' injury blow and City's subsequent defensive crisis later today on www.bradfordcityfc.co.uk