Millwall have released Shane Ferguson, as announced by their official club website.
Millwall have decided to let the winger move on this summer after five years at the club.
Ferguson, who is 29 years old, fell down the pecking order with the Lions over the course of the past season and is now becoming a free agent.
Charlton Athletic were interested in him in the January transfer window, as per journalist Richard Cawley.
Fellow League One side Portsmouth were also believed to be keen on landing him as well, as reported by Football Insider.
Ferguson is now available on a free transfer and it will be interesting to see if Charlton or Pompey rekindle their interest from the past winter.
He joined Millwall in 2016 and has since made 193 appearances in all competitions for the Lions, chipping in with 12 goals.
The Northern Ireland international played a key role in their promotion from League One under Neil Harris and has helped the London club establish themselves in the Championship over the past few seasons.
Ferguson played for Newcastle United before moving to Millwall and is now in the hunt for a new employer.
Charlton and Portsmouth were credited with an interest in January and may now be alerted by his availability.
Millwall have become one of the latest Football League clubs to announce their retained list, with Frank Fielding and James Brown also leaving.