In the 1978 summer, he moved to the second division and joined Rot-Weiss Essen, appearing almost exclusively as a midfielder during his spell, and scoring 36 league goals in his last three seasons combined.

Herget continued in the second level in the 1982–83 season, netting five goals in 35 games for Bayer 05 Uerdingen as the team promoted to the top flight after finishing third.

He continued to be an undisputed starter in the following years, also managing to score in every season during his seven-year stint, which included a best-ever third position for the club in 1985–86; additionally, he played the full 90 minutes in the final of the 1985 German Cup, winning the first and only trophy of his career after defeating FC Bayern Munich 2–1.

Herget made his debut for West Germany on 26 October 1983, replacing Hans-Peter Briegel for the last ten minutes of a 5–1 home win against Turkey for the UEFA Euro 1984 qualifiers.

He was part of the squad that finished second at the 1986 FIFA World Cup in Mexico, but only appeared once, in the 2–0 group stage loss against Denmark at Estadio Corregidora in Querétaro.