That's according to Calciomercato.com, who said Rossoneri sporting director Massimo Mirabelli is holding out on taking up the offer from Watford's executives as he wants to see whether the 20-year-old can maintain his fine form to the end of this season.
Calciomercato added the Brazilian striker has been linked to Chelsea, Tottenham Hotspur and Borussia Dortmund after netting five times and providing three assists in his first 14 appearances in the English top flight.
Per FourFourTwo, Richarlison was linked with the Blues before he made the switch to Watford, and it seems the Premier League champions are still interested in signing him up.
He only moved to Vicarage Road from Fluminense in the summer, costing Watford £11.2 million and signing a five-year deal.
But Richarlison has already starred under manager Marco Silva as the Hornets have made a fine start to the campaign—after 14 matches they sit eighth, four points off the top four.
Chelsea could do with a player of his quality to provide back-up and competition in the front line. The west London outfit's depth in attack is lacking, especially as manager Antonio Conte seems to be unwilling to play Michy Batshuayi in place of Alvaro Morata.
Richarlison could be an ideal second striker at Stamford Bridge, and he also has the versatility to cover other attacking positions.
But the link to Milan could cause problems for Chelsea's pursuit, while Watford are also unlikely to be willing to sell.
The Hertfordshire club recently moved to quash speculation their star man could leave in January, with chief executive Scott Duxbury saying there is no need for Richarlison to be sold, per Simon Johnson in the Evening Standard:
"We want Richarlison to be here for many more seasons. We are building a very competitive squad, we have no need to sell.
"We believe in the season being a race and that’s why we will never sell a player in January who we believe will help us. Nobody will be sold that we don’t want to. None of the players making an impact now will go."
Duxbury's comments are at odds with reports indicating Richarlison has been offered to Milan.
But if he continues to excel during the current campaign, then rumours of top European clubs being interested in the Brazilian are only likely to become more prevalent.