Damien Duff has confirmed he is leaving Celtic for family reasons after the "best year and a half" of his career.
The 41-year-old will now focus solely on his Republic of Ireland role, having been appointed Stephen Kenny's assistant in April.
As first-coach under Neil Lennon, Duff helped Celtic complete the treble treble and add a ninth consecutive Scottish Premiership title.
"It was absolutely a family decision," Duff said of his departure.
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"There is no job in the world that would have taken me away from the role I was in.
"For the first while I was away, my kids were like, 'Daddy, Daddy, stay for nine and 10', but as time went by, it was more, 'Daddy, Daddy, when are you coming home?'
"I'm gutted, but my kids need me, which is always the most important thing to any dad."