Millwall boss Kenny Jackett has signed Crystal Palace winger Dave Martin for an initial fee of £50,000.
Martin, 22, almost joined the Lions from Dartford in January 2007 before moving to the Eagles instead.
He made 15 appearances for Palace but has now put pen to paper on a two-and-a-half-year deal with Millwall.
Meanwhile, Palace have terminated the contracts of Stuart Green, 26, and Charlie Sheringham, 19, the son of ex-England international striker Teddy.
Green moved to Selhurst Park from Carlisle for £75,000 in August 2006 and played 27 games for Palace.
Sheringham, who began his career with Millwall and has also spent time with Tottenham, Ipswich and Charlton, has been on Palace's books since July 2006 without making a first-team appearance.
Martin's fee could rise to £100,000 depending on appearances.
Jackett told Millwall's website: "David will give us pace and balance as a wide left-sided player and I expext him to go straight into our squad to face Doncaster on Saturday."