Kenny Jackett now has his trusty lieutenant and ‘good foil’ by his side.
And Michael Calvin is convinced the pair represent an outstanding footballing combination.
Joe Gallen was announced as Jackett’s assistant on Thursday, marking the fourth time the duo have worked together.
The 44-year-old stood in the background during the manager’s unveiling a week earlier, yet has now been officially appointed.
Award-winning sports writer Calvin saw the double act at first hand during a season covering Millwall from inside the dressing room for his 2010 book Family: Life, Death and Football.
He said: ‘Joe is a top bloke – and a good foil for Ken.
‘Most assistant managers are like confessor figures, they have to be a bit more accessible to players than a manager.
‘A manager has to keep his distance and retain authority.
‘Joe is a good football man who comes from a great football family and the guy that the bloke out of form or guy worried about his place would go to.
‘Football is full of fear and insecurity and he is the sort of guy people have a quiet word with, asking him “what do you think?”.
‘They work well off one another.’
Calvin’s work on the 2009-10 Millwall campaign earned him a nomination in the 2011 British Sports Book Awards.
Yet his association with Jackett stretches from childhood.
He added: ‘We were kids together growing up on a council estate in Watford.
‘I’ve known him for far too many years.
‘Our dads, who have sadly passed away, were friends, my son is friendly with his son.
‘In essence, the last time I worked professionally with Ken was at Wembley against Wigan in the 2013 FA Cup semi-final.
‘I was in the dressing room. Football is a superstition business and I was previously on the bench and in the dressing room when they were promoted from League One at Wembley in the 2010 play-offs.
‘A couple of years later they were back and the players went to Ken and said “look, we want Mike in the dressing room because he’s our good luck charm”.
‘You get a flavour of the respect in the game for him from former players like Paul Robinson, who is a really solid citizen, a great bloke.
‘Then there’s Alan Dunne, who has previously voiced how Kenny Jackett had made his career.
‘What he does is inspire great respect and loyalty from his players. He has respect in the game – and that extends to former players.’