Winger David Worrall has joined Southend United on a two-year deal after his contract with Championship side Rotherham United was terminated by mutual consent last week.
The 24-year-old, who was just 12 months into a two-year deal with the Millers, scored one goal in four matches for the club after joining from Bury.
Worrall moved to Oldham on loan in January and made 18 appearances.
"He'll bring a huge amount to this club," said Southend boss Phil Brown.
"We identified him early on this pre-season as a target and someone we thought would really help our promotion push next season, but we knew there was lots of interest.
Worrall started his career in Bury's academy then moved to West Bromwich Albion as a 17-year-old, only to return to Gigg Lane in 2010.