The defender, City's Player of the Year last term, has been ruled out for between six to nine months after it was confirmed he ruptured his Achilles tendon during Saturday's 1-0 defeat at Burton.
Bradford lost both Oliver and fellow defender Andrew Davies (knee) to injury during the encounter, with a more exact diagnosis expected on the latter on Wednesday.
Manager Phil Parkinson told the club's official website: "Unfortunately, as we feared, Luke has indeed ruptured his left Achilles tendon. Our medical team thought as much after the match and now it has been confirmed.
"Luke has already had the injury operated on this morning (Tuesday) but we've been told he faces six to nine months out of action.
"With Andrew, he's having further tests and we should know more about his exact problem on Wednesday."