Addicks chairman Michael Slater took to the club's matchday programme to reject claims that the club may be sold, but Powell accepts that any of his players could be moved on to raise much-needed funds.
"I think everyone is up for sale at every football club bar Chelsea and Man City," said Powell, the former England left-back who took over at The Valley in January 2011.
"Everyone is available if they put the money down. I'm not saying that's what I want to happen here but you can't stop people bidding for your players if they're interested.
"It is always a fact of managerial life that anyone can come in for your players at any time during the transfer window."
Powell is hopeful of adding more players to his squad, with Tottenham striker Jon Obika linked with a return to The Valley following a loan spell that yielded three goals in the latter part of last season.
"We are going to be forever linked with him until he comes here or goes elsewhere," Powell added.
"Obviously Spurs have got bigger fish to fry they feel at the moment, and we all know what that is. He is someone we've looked at and will continue to monitor."