The 23-year-old midfielder, who joined Newcastle from AC Milan in July for £55 million ($69 million), had made just 12 appearances for the Magpies when he was punished.
On Thursday the English Football Association handed Tonali a suspended two-month ban and fined him £20,000 for breaches of betting rules following his move to Newcastle.
He will not serve the ban as long as he does not commit further breaches before the end of next season.
Newcastle, who exited in the group stage of this season’s Champions League, are currently seventh in the Premier League, 14 points off the top-four with just four games to go.
Howe, whose team face relegation-threatened Burnley on Saturday, was asked at his pre-match press conference what the club had missed in Tonali’s absence.
“His technical ability, his ability to play different positions in a season where you’re stretched by injuries,” he said. “Any player that is versatile is hugely important.
“He would have been a big, big player for us. He would have driven us to get some key results. The players have felt his loss as well. That has been a negative for the players to see him train and then not be able to play.”
The Newcastle boss said Tonali’s return would feel like a new signing.
“I think for us and for him from this situation, good comes of it, that he’s able to learn and develop to the English style and ultimately it could be something that he looks back on in a few years’ time and goes, ‘Actually, you know what? That helped me settle into England.”
© Agence France-Presse
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