Charlton boss Alan Pardew has agreed a release package for Uruguayan pair Gonzalo Sorondo and Omar Pouso.
Defender Sorondo, 27, was first signed on a season-long loan from Inter Milan in the summer of 2005 by former manager Alan Curbishley after the player had a 20-match spell with Crystal Palace.
But back and hamstring injuries and the bulk of a four-match suspension earned at Palace helped restrict him to just nine appearances despite signing a permanent deal with former Addicks boss Iain Dowie.
Pouso, another season-long loan from Penarol on the final day of the August transfer window, sustained a hamstring injury against Portsmouth in September and never played for the first team again.
Charlton have also revealed Andrew Mills, formerly the club's general manager of football, has left the club.
His appointment in May 2006 formed part of a new management structure at The Valley, spearheaded by Dowie.
Mills' main responsibility was to ease the workload of transfer business from chairman Richard Murray.
With Pardew at the helm Charlton have decided on a different transfer policy - although Mills was instrumental in helping secure the recent transfers of £2.5million Madjid Bougherra from Sheffield Wednesday, £500,000 Ben Thatcher from Manchester City and Alexandre Song's loan from Arsenal.
Alongside Dowie, Mills also helped bring Scott Carson (on loan from Liverpool), Andy Reid (£3million from Tottenham) and Souleymane Diawara (£3.7million from Sochaux) to the club.
Murray said: 'With me, Andrew secured all of the targets identified by Iain Dowie, as well as those by Alan Pardew during the January transfer window. I would like to thank him for all his hard work on behalf of the club.'