The Daily Mail has reported that Derby County have made a £7 million bid for the 26-year-old, who struck the winner in Sheffield Wednesday's opening day win against Aston Villa on Sunday.
Forestieri appeared 39 times scoring 15 goals last season in his first year at the club as the Argentine born attacker became a mainstay in the team under Carlos Carvalhal,
With just under a month to go until the window shuts, it's not hard to see why Wednesday must keep their main man.
Shift in mentality
Selling a star player would certainly create doubt in the players' minds, especially if it's to a Championship rival who are looking to gain promotion this term.
For Carvalhal it's important he builds Wednesday around players like Forestieri to attract other appealing players to the club, the manager has been reassured from the board that star players will not be sold, according to the Sheffield Star, although if a lucrative offer does come in they could be tempted to sell the player.
It will no doubt change the momentum of the club who've been on the up since the arrival of Carlos Carvalhal with the Portuguese tactician guiding them to the play-off final last season. The sale of such an influential player as Forestieri could have unexpectedly wide-reaching consequences.
The board have seemingly assured Carvalhal that players will not be sold, so if they do, where would it leave the relationship between manager and hierarchy at Hillsborough?
He's been able to change the mentality of the club: before the former Besiktas, Sporting CP and Braga manager, survival was the aim but he's been able to make the club push for the Premier League.
Carvalhal has formed a side which can compete for more than just mid-table, but breaking promises could potentially see a man they all adore at Wednesday leave.
Who could they replace him with?
Of course you can replace the former Watford man, but with less than a month to go in the window it will be hard to replace a player who fulfils the role of Forestieri.
The Championship is no easy division, so to find someone who can click with the team straight away will be difficult, the former Italy Under 21 international has more than enough experience and that certainly was evident last campaign with his mature, quality performances.
The Owls' star man has the ability to change the game by himself so if the club have aspirations of sustaining a Premier League promotion push they must maintain their prized asset.
A player who's been a revelation in Yorkshire will be subject of speculation throughout the rest of the window, but Wednesday will should be very wary of the aftermath if they decide to let Forestieri leave the club.