Mjallby and Lennon worked together at the end of last season
Johan Mjallby, Alan Thompson and Garry Parker have been confirmed as Neil Lennon's backroom staff as Willie McStay exited Celtic Park once more.
Mjallby is Lennon's assistant, having filled that role while the former Celtic midfielder was caretaker boss.
Thompson had already been announced as first-team coach on leaving Newcastle.
Parker will also be a first-team coach, but McStay, who had returned after a spell as Ujpest manager, does not figure in Lennon's plans.
McStay, 48, who had spent 15 years as youth then reserve coach at Celtic, had been linked with the managerial vacancies at Kilmarnock and St Mirren on returning to Glasgow this summer after a season in Hungary.
Garry's built up quite a resume and poached some players as well, not just in England but further afield too
Celtic manager Neil Lennon
Lennon has, meanwhile, surrounded himself with former team-mates, having played with Mjallby and Thompson at Celtic, and Parker at Leicester City.
"They are different personalities, but we all have the same ideas on the club," he told Celtic's website.
"Alan and Johan both played here and are delighted to be back. Johan has vast experience, he captained his country at the World Cup and was a great player here, as was Alan.
"Johan was with me for the last few games and was fantastic for me. The two of us made the most of an opportunity that was there, but he needed assistance and I'm delighted the other two can come and join us."
The 39-year-old Mallby spent six years in Celtic's defence in between two spells with AIK in his Swedish homeland.
Parker had a spell as caretaker manager at Leicester
Thompson had been academy coach with former club Newcastle after ending his career with Leeds United, the 36-year-old having also played for Bolton Wanderers and Aston Villa.
Fellow Englishman Parker became friendly with Lennon as the 44-year-old ended at Leicester a playing career that also took in Luton Town, Hull City, Nottingham Forest and Aston Villa.
"Garry was with me at Leicester and we have been in constant contact over the years," said Lennon of the man who had a brief spell as Leicester's caretaker manager in 2001.
"No matter where I would have gone, I would have taken Garry with me. This opportunity came and he's delighted to come up.
"Garry played for Forest under Brian Clough for a while and has played in quality teams. He's played at Premiership level for all of his career and has a good footballing brain.
"He has a good eye for a player as well, so he'll help me on the talent side of things.
"He's been scouting at clubs for three or four years now, so he's built up quite a resume and poached some players as well, not just in England but further afield too."
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