Birmingham City have already made a £3m enquiry ahead of the January transfer window, only to be told in no uncertain terms that the Duke isn't for sale.
And if he continues to knock in the goals – he has 11 to date – the club know that the level of interest in him will increase.
Manager Paul Jewell told a fans' forum organised by the supporters' club that talks with Ellington's agent would hopefully start soon.
He said: "There is no chance that he will be leaving. Birmingham did come in with an offer for him but to be honest, Birmingham couldn't afford him.
"We are planning to offer Duke a new contract soon.
"We are definitely not a selling club. If a player came and said he wasn't happy here then he could go.
"But the Duke is happy here and loving his football, so he's staying."
On a similar topic, Jewell also revealed that 15 players in the first-team squad would be out of contract at the end of this season.
Goalkeeper John Filan has already had new terms put on the table but talks with the others would only start at Christmas.
If Filan does accept the deal it will be his last in English football before he returns to live in Australia.
Jewell said: "We've offered John a new contract and when that's finished he is going home.
"I think he is the best keeper in the Championship and could play at Premiership level.
"There are 15 players out of contract at the end of the season so this is a big year for us.
"But we must see where we are at Christmas and then talk. At the moment we will continue just to play."
Those out of contract next summer include Lee McCulloch, Gary Teale, Ian Breckin, Jason Jarrett, Nicky Eaden, Matt Jackson and Steve McMillan.
On the recruitment front, Jewell says he has looked towards the Continent in an effort to bolster the size and quality of the squad for a sustained promotion push.
He travelled to Denmark recently to run the rule over some young players, having been frustrated in his efforts to land players from English clubs.
Lifting the blanket of secrecy over the identity of his recent transfer targets from the Premiership, Jewell said he had tried to sign Scott Parker from Chelsea, Liverpool's Igor Biscan, Michael Carrick from Spurs and Manchester United's Scotland midfielder Darren Fletcher.
But either the players had refused to drop down to the Championship or their clubs had been unwilling to let them leave.
Jewell said: "With the transfer window, Premiership clubs don't want to let players out and those in the Champions' League want to hold on to players in case they need them to play.
"I was in Denmark the other weekend watching some players because of that."
l Latics have sold around 2,600 tickets for Sunday's game at Leeds – more remain on sale at the JJB.