Brentford defender Karleigh Osborne is set to leave Griffin Park after turning down a new contract at the League One club.
The 23-year-old centre-half, who is currently sidelined through injury, has been linked with a move to League One leaders Charlton.
"He has turned down the contract we offered him so if someone comes in he is available for transfer," said manager Uwe Rosler.
"We cannot allow our players to go on Bosmans."
Rosler is also looking to add to his squad this month and said: "We are working on certain things but at the moment there is nothing signed."