The 30-year old has suffered with a catalogue of injury problems throughout the course of this season, losing his place to the excellent Talal El-Karkouri in the process.
Reports over the last few days have been suggesting that the South African could make the short switch across London in a cut price £100,000 deal providing that the Addicks can sign a replacement.
Fish angered Bolton manager Sam Allardyce when quitting the Reebok Stadium to move south in November 2000. The former Lazio man had agreed to extend his three-year stay in Lancashire only to go back on the contractual agreement at the last minute.