No formal bid has been made for Bridges, but sources in the North-East suggest that right-sided defender Andrew Griffin will be offered as a makeweight.
Bridges has been a target for Sir Bobby Robson for a number of months, but cash is also in short supply at St James' Park, like most clubs these days.
Fulham and Celtic are also understood to be keen on Bridges and both will almost certainly keep a close eye on the situation.