The 44-year-old stepped down as chairman of the Premier League side on Monday and was replaced by owner Short.
The Black Cats are currently 16th in the league table, taking only six points from a possible 21.
Despite pressure looming on Bruce, the former Republic of Ireland international believes that he has "time" to turn it around.
"Steve is not isolated by this, it's the exact opposite," the Daily Mail quotes Quinn as saying. "It's time for him to build a closer relationship with Ellis.
"Steve will get time for this team to gel. There's another window looming. Unless the situation becomes apocalyptic, and it's no good worrying about that, Steve will get time."
Quinn remains within Sunderland working with the club on international development.