Adam Barrett joined Millwall in March 2017 as a First Team Development Coach to assist Neil Harris and David Livermore.
The former centre-half, who amassed 735 appearances for a number of clubs, including Plymouth Argyle, Bristol Rovers, Bournemouth, Gillingham and, most recently, Southend United, retired from his playing career with The Shrimpers in the January.
As such, the experienced ex-defender brings a wealth of experience to The Den.
Barrett took over as caretaker manager at the club in October 2019, following the departure of Neil Harris.
Goalkeeping Coach: Lee Turner
Lee Turner joined The Lions in the summer of 2018 and became the club's Goalkeeping Coach.
The 48-year-old spent the entirety of his playing career in non-League, but has coached at Southend United, Crystal Palace, Bolton Wanderers and Charlton Athletic, overseeing the development of stoppers such as Nick Pope and Ben Amos.
Turner assisted Millwall's crop of goalkeepers in 2018/19, including Jordan Archer, David Martin and continuing his work with Amos.