The 29-year-old was stripped of the captaincy by Unai Emery in October 2019 after swearing at supporters who were cheering his substitution.
The forward has been in Germany to put the finishing touches to a ÂŁ25m move back to the club he left for Chelsea in 2020.
Tottenham have won the race to sign the highly rated Destiny Udogie while Nicola Vlasic is set to join Torino on loan