On the workrate and physicality talk, I'll offer my opinion because I saw pretty much every performance of his at Sunderland. His loan was one of the easiest to keep up with because not only do Sunderland upload the full 90 minutes of all their games to their YouTube channel, this channel -
https://www.youtube.com/@worldfootballhighlight/videos - made in depth highlight videos of all his performances. Not your typical highlight videos that leave out a players mistakes. Everything is included, from his touches to his off the ball movement to his pressing and defensive positioning.
Basically, he really bulked up and ended up dealing with the physicality of the league well, and he showed a good work ethic. There were times where he'd lose the ball cheaply and, instead of going to win it back, he'd throw a strop, but, for the most part, he was very intense with his pressing, did well at supporting his full back when on the right, and tracked back to help the central midfield when playing centrally. Personally, I wouldn't worry about his strops because I think that was partly the result of he himself thinking he was Sunderlands best player whereas, here, I don't think he'd have that attitude as he'd know he isn't one of our best.
I don't know how the injury is going to impact him upon his return but, if he gets back to the level he showed last year, I definitely think he can make a positive contribution. He wouldn't have looked out of place in terms of the intensity the likes of Garnacho, Hojlund and Antony showed against Chelsea for example.