The England international will move across Birmingham and join West Brom in the next 24 hours on a season-long loan deal with a view to a permanent ?4m switch next summer - as revealed exclusively by Sportsmail last week.
Foster will also be joined by team-mate Liam Ridgewell who is also leaving following a ?2m switch as the sell-off from the relegated club shows no sign of letting up.
Exit: West Bromwich Albion are in talks to sign Birmingham goalkeeper Ben Foster
Argument: Paul Trollope tried to stamp his authority by pulling Foster up for being late to training
But it is the keeper's exit that will leave a bitter taste following a bust-up with Hughton's right-hand man Trollope at the club's Wast Hills training base.
The former Wales international has only been in the job a matter of days but his attempt to bring the 28-year-old back into line backfired spectacularly -in front of a startled dressing-room.
Problems arose when Foster arrived ten minutes late to training on Monday morning.
He completed the session but was then pulled about his tardiness by the former Bristol Rovers' boss.
There was a full and frank exchange of views between the pair with Foster questioning Trollope's credentials before speeding away.
A source said: 'If this was an attempt by Trollope to establish some discipline, it didn't work. Foster directly challenged his authority before getting into his car.'
It is the latest in a series of setbacks to rock last season's Carling Cup winners whose acting chairman Peter Pannu has finally admitted that he will have to make some 'unpopular decisions.'
However, there was some good news at last for the beleaguered Hughton who watched his side slump to a 2-0 defeat against Oxford United on Monday night. He is on the verge of completing a move for ex-Wolves midfielder Dave Jones.
Hughton is also locked in talks with the Baggies over Wales international Boaz Myhill. Myhill does not fit into Roy Hodgson's plans but has vowed to fight for his place in the team.
'It is frustrating to see the club continually linked with moves for a new goalkeeper, but there is nothing I can do about it,' Myhill told skysports.com.
'I will just get my head down and work hard and try to impress Roy Hodgson.'
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