The 33-year-old striker was released by the Addicks at the end of last season.
He could, however, be drafted back into The Valley ranks for 2013/14 after spending the summer training with Charlton.
Powell says he would be prepared to put terms to the former Stoke man if he indicated that an agreement was possible.
Fuller has admitted to having options to consider this summer, but has also revealed that his preference would be to remain at Charlton.
On the situation as it stands, Powell said in the South London Press: "Ricardo was one that I always left the possibility of bringing back.
"I don't know about other options that he may have.
"I just shook his hand, told him it was good to see him and he has got on with his training. Maybe there is a conversation to be had."