But Doughty told BBC Radio Nottingham: "Billy's here for the long-term. We've asked him to build a club and I think he's accepting that challenge.
"He's done a marvellous job and I think we have a good working relationship."
Doughty added that he was disappointed at Tuesday night's play-off defeat to Blackpool but the club intends to regroup.
"Whatever would have happened on Tuesday or at Wembley we would have had the same strategy, which is to invest sensibly and consistently.
"We're assembling a very attractive, maturing young squad - the youngest squad in the Championship and we'll carry on with that strategy."
"We're a young talented squad that's only going to get better is my impression and what people around the club tell me."