Wigan chairman Dave Whelan expects to name Roberto Martinez as the club's new manager on Wednesday.
Martinez, 35, is poised to leave Swansea and succeed Steve Bruce, who has moved to Sunderland.
"Everything is almost agreed, the only reason it has not been signed up is because I'm in Majorca," Whelan told the Evening Post.
"I'm due back on Wednesday, the deal will be completed then, and we'll have a press conference on Thursday. I hope that Roberto stays with us for quite a long time.
"I was really sad to lose Steve Bruce, who was a great manager for Wigan but Roberto is a wonderful man who knows football inside out."
Martinez guided Swansea to the Coca-Cola League One title last year and then finished within two places of the Championship play-offs last season.
He met Wigan chief executive Brenda Spencer last week to begin negotiations after she was given permission to speak to him once a compensation deal was agreed.
Should the move go through as anticipated - Spencer confirmed they had held "positive talks" - it will complete a remarkable journey for the Spaniard.
He joined the club 1995 and stayed six years, plying his trade in England's lower leagues before eventually turning his hand to coaching and management.
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