The Italian was banned for most of last season due to betting violations, and still has to bide his time before he can return.
However, Tonali has been keeping very fit, with Hall admitting that the Italian is raring to go when he can play again.
"It's been really difficult for Sandro," Hall told ChronicleLive.
"I talk about me and my setbacks, but it has been a lot harder for him.
"I know the extent of what he has had to deal with and he's dealt with it quite well. He's not just moved from the opposite end of the country, but a completely different country.
"It must not be easy for him at all, but he's come back to pre-season and really worked hard and has got the quality that we all know he has. All the lads can't wait for him to be back and helping the team.