Former player John Collins is to join new Celtic boss Ronny Deila as his assistant at Parkhead, the club announced on Tuesday.
The former Scotland international midfielder, who made 229 appearances for Celtic from 1990 to 1996, said he was delighted to rejoin the club and work with Delia.
The Norwegian took over the post of manager earlier in the month following the departure of Neil Lennon.
"It is a huge honour for me to return to Celtic, the club which has always been such a major part of my life," Collins told the club's official website.
"I am grateful to Ronny for giving me this wonderful opportunity and I look forward to working closely with him and the players to ensure that we can continue to bring the good times to Celtic.
"I know what a great club Celtic is and I know exactly what the club means to our fans.
"I will support the manager in every way and I am sure that together with our players, the backroom staff and the fans, we can all play our part in bringing success to the club."
Collins, 46, started his career at Hibs and also played for Monaco, Everton and Fulham and was capped 58 times by Scotland.
He won the League Cup in 2007 as Hibs manager and had a spell as boss of Charleroi in Belgium and as director of football at Livingston.
A delighted Deila said: "I have had a number of meetings with John, I can see what the club means to him and I can see the qualities that he will bring to Celtic.
"He is a first-class coach and has ideas on football which are very similar to mine so I am sure he will be a great addition to my team."
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