Tommy Wright has resigned as manager of Lisburn Distillery and is expected to be named as assistant to Steve Lomas at Scottish Premier club St Johnstone.
Wright is believed to have told the Whites' players of his departure at training on Tuesday night.
Lomas and former Ballymena and Limavady manager Wright are set to be unveiled as the new management team at St Johnstone on Thursday morning.
Wright had been in charge at Distillery since September 2009.
John Cunningham and Glenn Ferguson will take temporary charge of Distillery.
The pair, who have been part of Wright's backroom team, will be in the dugout for Saturday's game against Donegal Celtic.
The Whites lie ninth in the Premiership, with just three wins from their 14 league games.
Wright succeeded Jimmy Brown as Distillery manager and guided the club clear of the relegation zone.
Last season the former Northern Ireland international goalkeeper led the Whites to victory in the Co-operative Insurance League Cup and also secured a top-six finish in the league.
Lomas and Wright were team-mates at Manchester City during their playing careers and were also part of the Northern Ireland squad.
Lomas is believed to have been interviewed by representatives of Scottish Premier League club St Johnstone and the Perth club have called a press conference for 0930 GMT on Thursday.