New Delhi, May 8 -- Champions League winner and five-time Bundesliga champion Niklas Sule has announced his retirement at the age of 30 after an injury scare led him to reconsider his future.

The Borussia Dortmund and Germany defender is leaving soccer at the end of the season, when his contract at the club was already due to expire.

"I'm very, very clear about my decision," Sule said on the Spielmacher podcast in an episode released Thursday. "Despite that, football has given me a huge amount and I had such a great, cool time that there's pain in saying this."

Sule has missed 22 games with various injuries this season and said a moment of clarity came after he hurt his knee in a game against Hoffenheim last month.

Sule said he "cried...