The 25-year-old midfielder is wanted at Arsenal, who have proposed to sign him on loan for the rest of the season.
The Gunners are also prepared to cover his full wages until the end of his loan stint and have been waiting for Juventus to make up their mind about the Brazilian.
But Allegri has made it clear that he wants the current squad to remain intact and is not in favour of loaning out Arthur in the ongoing transfer window.
And according to Italian outlet Calciomercato.it, his performance in their 4-1 win over Sampdoria on Tuesday night has further emboldened the Juventus coach.
The Italian is pushing to keep Arthur at Juventus for the rest of the season and is counting on him as an important player.
However, it has not been ruled out that Juventus will loan out the player before the end of the window.
But for the moment, it seems Arthur could continue at the Turin club beyond the end of this month.
Juventus are also not keen on a simple loan until the end of the season and want an 18-month loan offer.
Arsenal remain at the window for Arthur but for the moment it seems likely he will stay at Juventus.