The Birmingham midfielder had his loan spell at Forest cut short after just four appearances due to recurrence of a knee injury.
But Davies is keen to bring the playmaker back to the City Ground so long as he can prove his fitness.
"Before Gary left we had a good conversation and my advice to him was simple - he has to get back to loving football," Davies told his club's official website.
"He left under no illusions as to what I was saying. He is such a wonderful talent but he has to get 100 per cent fit and be willing to fight tooth and nail to get back to being one of the best players in the Championship again.
"I don't know what Birmingham's thoughts are, but at moment we are preparing a list and McSheffrey is on it. There are not too many of his quality on his day but he has to be right."