[8] On 10 December 2016, Jung gave an assist to Roger from a free kick to inflict RB Leipzig's first defeat in the 2016–17 Bundesliga, ending their run of 13 unbeaten league games.

[10] In July 2017, Jung joined Danish Superliga club Brøndby IF on a one-year loan deal reuniting with former RB Leipzig coach Alexander Zorniger.

On 10 May 2018, he made an appearance as Brøndby defeated Silkeborg 3–1 in the Danish Cup final; the club's first silverware in 10 years.

[16] He soon evolved into a starter for the club, first as a left-back, and later under head coach Niels Frederiksen, as a centre-back in his 3–5–2 formation.

[17] Jung scored his second goal for the club on 16 February 2020 in a 2–0 away win over OB, a tap-in early in the match.

[21] Jung finished the 2019–20 season with 40 appearances across all competitions, including qualifiers for the UEFA Europa League, scoring three goals – all in the Superliga.

[27] He reached promotion back to the Bundesliga with Werder in his first season at the club, making 30 appearances in which he scored two goals.