Boco was released by Plymouth Argyle this summer after joining them from Cook's old team Accrington Stanley, and the manager said that there could be a deal in the pipeline.
"He's a good friend of mine," Sky Sports News quotes Cook as saying. "With him not having a club it's an opportunity for him to come and train with us. At the minute that's all that is.
"We are looking for players, as everyone knows, and if Romy can get his fitness and enjoys training with us then you never know in football. No-one ever knows that, it's not something we're actively trying to do at the minute but you never know."
Boco scored once in 27 games for Plymouth last season.