Gundogan's exit comes as a shock, especially after he played a crucial role for Barca last season. Despite his contributions, the experienced midfielder was informed by the club's new coach, Hansi Flick, that his starting spot was no longer guaranteed.
However, in a farewell message to Barcelona fans last month, Gundogan hinted that his decision to leave was partly motivated by a desire to help the club alleviate its financial difficulties.
“I have given everything to fight for the team and the club the best possible way in a difficult season and I was looking forward to helping my teammates in the new campaign," he wrote.
“Now I am leaving in a difficult situation, but if my departure can help the club financially, it makes me a bit less sad.”