Chris Coleman is set to be unveiled as Sunderland boss within 48-hours after resigning from his role as Wales manager.
The 47-year-old had been Wales boss for almost six years and last summer guided his country to the semi-finals of Euro 2016.
The new challenge facing Coleman will be to steer bottom-of-the-table Sunderland up the Championship and away from relegation danger, with his appointment expected to be confirmed by Sunday.
Caretaker boss Robbie Stockdale will take charge of the Sunderland side for the visit of Millwall, with the Black Cats aiming to avoid holding the English record outright for the longest ever home winless streak.
Sunderland have gone 19 games without a home win in all competitions but the imminent appointment of Coleman will give Sunderland a major lift heading into the game.
Kit Symons has also left his coaching post at Wales and the former Fulham manager could be heading to Wearside with Coleman, with the new management team set to be in charge for Tuesday night's trip to Aston Villa.
Coleman resigned from his position as Wales manager on Friday with immediate effect and officials at the FWA have expressed their bitter disappointment but added that Coleman had always held a strong desire to go back into club management.
His future as Wales manager had been in doubt while he waited on assurances regarding members of his backroom staff and he is now set to take over from Simon Grayson, who was sacked as Sunderland manager on October 31.
An FAW statement read: "Regretfully, Chris Coleman has resigned from his position as Wales National Team Manager with immediate effect.
"Chris was appointed manager in January 2012 in very difficult circumstances and has guided Wales to the semi-finals of EURO 2016, an incredible achievement that inspired a nation.
"Kit Symons has also resigned from his position as National Team Coach and the FAW would like to put on record its gratitude for his commitment to the Wales National Team."
Jonathan Ford, Chief Executive of the Football Association of Wales, said: "We are extremely disappointed to see Chris’ tenure as Wales manager come to an end.
"The FAW and Wales as a nation will be eternally grateful for the job he has done over the last six years as National Team Manager, from travelling the length and breadth of Wales outside of the media spotlight to talk to players and supporters, to guiding us to the semi-finals of the European Championships.
"We wish Chris the very best of luck for the future as he returns to club management, a desire for which he has always been honest and open about."
The Black Cats had identified Coleman, who oversaw 50 games in charge of Wales, as their number one target following the departure of Simon Grayson over a fortnight ago, with chief executive Martin Bain overseeing a lengthy recruitment process.
Former Fulham and Coventry City boss Coleman will team up with Wales internationals Jonny Williams, on loan from Crystal Palace, and right-back Adam Matthews at Sunderland - both of which have played under Coleman at international level.
The former Wales boss spoke about Sunderland in glowing terms in September when Williams joined the Black Cats on deadline day.
Coleman, speaking in September said: "Jonny finished training, in a car, straight up to Sunderland, medical, agreed everything. Text me last night, all done, he arrived back at the hotel at 5 o'clock this morning.
"But he had a big smile on his face, he's going to an incredible club and I think they'll like his football up there. It's a very shrewd move."