Madine moved to Leeds' promotion rivals, Sheffield United, on loan at the start of the winter window, a year after signing for Cardiff City in a deal reportedly worth £6 million [BBC].
The Geordie striker helped Cardiff to promotion last season and will be looking to repeat the trick with Sheffield United this campaign.
But while the Blades have also added Scott Hogan to their attacking options, Leeds will have to make do with what they have got between now and the end of the season.
And Whelan concurred with his former Elland Road teammate, adding: "We had the conversation didn't we, the other day, Deano, about Gary Madine?
"We thought he would have been a great deal for Leeds. You know - physical, strong.
"And because we play so much down the width, you know, you don't have to put it perfectly on his head, put in the right areas and he'll make it a good ball."
Sheffield United, for whom Deane also played, can overtake Leeds and Norwich at the top of the Championship with a win against Aston Villa this evening.