The right-back, who made the move to the City Ground last week, has not been a part of Paul Lambert's plans this season.
And the 27-year-old, while refusing to be drawn on why he has fallen out of favour at Villa Park, is relishing the chance to help Forest push for promotion.
"I don't see any way back for me at Villa. What's been said has done it for me there," said the Scotland international.
"It has been very frustrating. I want to play and through different circumstances I've not.
"But you have to go out and make the best of it. Forest is a big club and I want to be part of it.
"You'll have to ask Paul Lambert why he's not played me. I don't really want to go into it.
"New managers come in and have their own ideas. That is just the way things go."