The 19-year-old has enjoyed a productive loan spell in Germany this season, scoring seven goals in 22 Bundesliga games.
After playing his final game for the German club against Mainz on Saturday afternoon, he is expected to link up with Unai Emery’s Arsenal squad in pre-season.
Hoffenheim tweeted: “You are pure football joy. Today once again give everything for those. #TSG After that, we wish you every success and all the best on your way forward! #Goodbye.”
It has not been plain sailing for Nelson, however, as the England Under-21 international was left out of the Hoffenheim squad for their 2-1 victory over Nurnberg in March.
Manager Julian Nagelsmann described his omission as an ‘educational measure’.
And Nelson believes his loan spell in Germany has made him grow up.
He said: “I was late to training, I was 20 minutes late, and that’s something I need to learn from.
“You can make mistakes but it’s your job and you shouldn’t be late. I held my hand up and I said sorry to him and we both moved on as bigger men.
“He put me in the squad the next week because I’d been doing well. I’ve been out there for ten months by myself. It’s not been easy and I haven’t had my mum or my brother about.
“I’ve got to do my own shopping, I haven’t got many friends out there but it’s my job and I’m there to play football.