The Italian international was handed a 10-month ban after admitting multiple breaches of gambling rules during his time with Brescia and AC Milan.
The 23-year-old's agent, Giuseppe Riso, admitted Tonali is struggling with a gambling addiction and now the Telegraph reports he could face an even longer ban if found to have placed bets following his £55 million ($68m) transfer from Milan.
The report states the Italian has co-operated fully with the FA and are waiting to hear if any further action will be taken against the summer signing, who cannot play again for Newcastle until the end of August 2024.
It adds that the FA are likely to decide Tonali has been punished enough, given the Italian Football Federation's ban applies worldwide and will decide their own punishment, if any, will run concurrently with his existing ban.
Newcastle's director of football, Dan Ashworth, said on the matter on Friday: “All I can say to you is that we have fully cooperated with all of the associations and organisations concerned and the FA are, of course, fully aware of what’s going on.
“They are the ones who had to sanction the ban so we’re fully cooperating with everybody. All I can deal with is the present and the facts. I can’t look into the future and [if the ban will be extended].
“I can’t speak for the owners or the board. All I can say is that we’re all disappointed that we’ve lost a player of Sandro’s calibre for 10 months.
“In my experience with the board and the owners, they are incredibly supportive and empathetic people who want to support their family. I know Sandro has had some messages of support from board members."