The Swiss footballer was the captain of Arsenal for six weeks in 2019 before being stripped of the leadership role following a clash with the club fans.
Granit Xhaka has made 293 appearances in the Premier League with Arsenal.
Sunderland, under manager Regis Le Bris, have already invested £107 million this summer on six new additions after getting the promotion to the Premier League.
With close to 300 appearances for Arsenal and two FA Cup titles to his name, Granit Xhaka’s Premier League credentials are firmly established
Hosts Leverkusen set up a new German record as they moved past Mainz with a 2-1 win on Saturday.
In the final minutes of the game, Xhaka received his second yellow card of the match for his headbutt on Katic.
The Gunners registered a massive 4-0 win as Chelsea suffered their second consecutive defeat.
Arsenal may have won over a fan for life through the gesture of Xhaka.
Granit Xhaka tested positive for coronavirus on Wednesday, the Switzerland national team confirmed.