Eintracht Frankfurt have admitted it was "painful" to grant Martin Hinteregger his wish to retire two weeks after his links to a far-right political figure in Austria emerged.
The defender, 29, had a year remaining on his contract with the Europa League winners but has taken the decision to step away from the game having faced a fierce backlash for organising a youth tournament, the Hinti Cup, in his hometown of Sirnitz with former business partner Heinrick Sickl.
It has since been revealed that Sickl was a member of a Neo-Nazi organisation in the 1990s and has rented property to the far-right Identitarian Movement Austria.
Once those allegations became public, Hinteregger sought to distance himself from Sickl. While he reiterated his regret around the Hinti Cup when confirming his retirement on Thursday, the centre-half claimed that he was contemplating stepping away from the professional game months ago having started the 2021/22 campaign in poor form.
"Last autumn, I'd already started to think about retiring at the end of the season. I was in a difficult period on the pitch: my performances were shaky," Hinteregger said.
"The wins didn't feel as good anymore, and every defeat hurt twice as much. My improvement in the spring and our joint successes in the Europa League made me even more motivated to bow out with a great sporting success.
"That's why I enjoyed the Europa League victory so much, because I already knew it would be my last big victory celebration with the fantastic fans in this city, which has become my second home.
"I will think back on my time with Eintracht with only great gratitude and joy, continue to feel closely connected to the club and their fans, and support the team as a fan on their continued journey in Europe.
"I thank my teammates, the coaching staff, the backroom staff, all the employees and the sporting management for the faith, the support and the wonderful time I've experienced here. Above all I thank the fans, who have always been behind me, including and especially in difficult times."
Those difficult times included battles with his mental health, with the former Red Bull Salzburg player earning praise for writing about his depression in a recent autobiography. However, the reaction to the Hinti Cup led Hinteregger to want to "get some distance and readjust my life".
He added: "In the past few weeks, a number of issues have arisen around my 'Hinti Cup', which I have run with passion and the best intentions, the implications of which have only become clear to me in retrospect.
"Some emotional and perhaps ill-advised words from me have caused irritation and I would like to apologise for that. I regret that very much. To make it clear once again: I condemn right-wing, intolerant and inhuman ideas in the strongest possible terms. Those who know me know that.
"For now, I need to get some distance and readjust my life. I'm grateful that Eintracht have given me the opportunity to take this step now."
Eintracht Frankfurt sporting director Markus Krosche said that the club was taken by surprise by the player's decision to retire but they made it clear he is welcome back any time having displayed sincerity when apologising for the relationship with Sickl.
"Martin's decision came unexpectedly, but he has presented his reasons to us clearly and convincingly. Therefore, it was the obvious choice to grant his wish, which is painful for us from a sporting point of view, but personally understandable," Krosche said.
"Martin will always be welcome in Frankfurt, not just as a proven player and European Cup winner, but also due to his sincere apology for his behaviour in recent days and weeks, and for his clear and convincing distancing from far-right ideology."
Reports in Austria suggested that Hinteregger might now play as a striker for his hometown club, who are in the amateur fifth tier.