Madine, who was born and raised around 10 miles from Sunderland in Gateshead, was allowed to leave Cardiff by mutual consent on Thursday.
It follows two goalless years in Wales, although the £6 million arrival from Bolton Wanderers did find the net three times while on loan to Sheffield United last season - helping the Blades to promotion.
It was at Bolton that Madine played under the now Sunderland manager Phil Parkinson.
And with Parkinson having made no secret of his desire to recruit another centre-forward, the following supporters of Sunderland, Cardiff and some others are putting two and two together...
Gary madine to sunderland like lads? Or just another charlie wyke? #safc— Big Dan (@Dan_h1993) January 9, 2020
How on earth did we get £6 mill for Madine & now he’s just been released on a free definitely going Sunderland now though #bwfc— Stephen Smith (@Stesmith1992) January 9, 2020
Off to Sunderland nailed on— Stephen Smith (@Stesmith1992) January 9, 2020
Gary Madine to #SAFC now makes an awful lot of sense. Amazed that Cardiff have happily just written off the contract of a player they paid £6m for twelve months ago though. Their fans in the comments of the announcement tweet seem a bit gutted that he's going.— Gav. (@Gav1879) January 9, 2020
This could be a complete game-changer for #SAFC. Sign Gary Madine - the ideal reference point for employing a direct style at League One level - and I expect them to really start to motor into that top six. https://t.co/cTJfHUIs8I— Gabriel Sutton (@_FootbalLab) January 9, 2020
Off to Sunderland , wyke and Madine up front means even more hoofball— - (@t0msafc) January 9, 2020
Whether Madine, who has spent the past two-and-a-half years playing Championship or Premier League football, would consider a drop to League One remains to be seen.
And the same goes for Sunderland's chances of being able to afford the 29-year-old, who is likely to have been on big money at Cardiff.
Have something to tell us about this article?