Linfield defender Chris Casement has agreed to sign for Portadown on a three-year contract.
The 23-year-old former Dundee player, who can also play in midfield, has struggled to hold down a regular place in the starting line-up at Linfield.
He spent half a season on loan with the Windsor Park club in 2010, before agreeing a two-year deal in July.
The Ports have already added Darren Murray to their squad, but have lost Matthew Tipton to the league champions.
Welsh-born forward Tipton announced last week that he had joined Linfield, while Murray has moved to Ronnie McFall's outfit from Donegal Celtic.
Meanwhile Ross Redman, Gary Breen and Neil MCCafferty have all committed themselves to Portadown for another two years.
Defender Brian Gartland has also agreed a one-year extension to his contract.
Wesley Boyle and Conor McCloskey are leaving the Shamrock Park club.