The head coach has confirmed the club’s top scorer for the last two seasons, rated in the £8m bracket, turned down a new contract during the close-season.
But Wagner also said no serious offer was received for the former Bradford City man during the last transfer window.
And as he prepares for Monday’s visit of Wigan Athletic, the German team chief said it’s business as usual for the Bermuda international, whose current deal ends the summer after next.
Wells, a then-club record £1.3m signing from neighbours Bradford City in January 2014, has scored 42 Town goals.
Three of them have come this season, and the 26-year-old has featured in the last 16 games after missing the first two of the campaign through injury.
“January is approaching and we have talk about Nahki, just as we have in other transfer windows,” said Wagner.
“But for me, it is very easy to leave this talk behind.
“Nahki was offered a new contract in the summer and he turned it down. We left the discussions behind us.
“We wanted to focus on this season, and we can talk again about a contract when the time is right.
“No serious offer was received in the summer, if we get one in January, it will be considered.
“But why waste energy and time talking about something that hasn’t happened?
“Nahki is still our player, and I would like to keep him. I have no aim to sell.
“He is a very good footballer, a natural scorer, and an important player for us.
“He suits our style and our style suits him, and I have no worries about his attitude amid this talk.
“Sometimes it is not easy to leave it totally behind when you are on the grass, because we are all human.
“But Nahki has a great approach to training and he is desperate to help the team and score goals.