Derby County manager Nigel Clough has confirmed his end of season retained list.
Striker Chris Porter, who was Clough's first signing for the Club in January 2009 from Scottish Premier League side Motherwell. will not be re-signing for the Rams.
Porter, 27, has found his time at Pride Park disrupted by injuries and made 25 starts, and a further 25 appearances from the bench, during his two-and-a-half years with Derby.
He scored nine goals in those appearances, including a brace in the 2-1 win at Preston North End in January 2011.
The Rams have also informed winger Greg Mills, who has spent the majority of the season on loan at AFC Telford United, and Arnaud Mendy that they will not be offered fresh terms.
Clough has also confirmed that goalkeepers Saul Deeney and Ross Atkins will be offered new deals while the option has also been taken up on James Severn's contract to remain with the Rams for a further year.
Trio Brad Jones, Daniel Ayala and Alberto Bueno will also be returning to their parent clubs at the end of their loan deals.
Out of contract and not being offered new deals: Chris Porter, Greg Mills, Arnaud Mendy, Robbie Savage (retiring).
Out of contract and to be offered new deals: Saul Deeney, Ross Atkins.
Players under contract beyond summer of 2011: Stephen Bywater, Frank Fielding, John Brayford, Gareth Roberts, Paul Green, Shaun Barker, Dean Leacock, Steven Davies, Jamie Ward, Stephen Pearson, Russell Anderson, David Martin, James Bailey, Jake Buxton, Tomasz Cywka, Ben Pringle, Miles Addison, Ben Davies, Conor Doyle, Jeff Hendrick, James Severn, Ryan Connolly, Lee Croft, Luke Varney, Mark O'Brien.
Returning to parent clubs after loan deals: Brad Jones, Daniel Ayala, Alberto Bueno
In addition, Academy youngsters Callum Ball, Alex Witham, Aaron Cole and Chris Jones will become first-year professionals next season after completing their scholarship programmes.