The 29-year-old lost his first-team position before the start of the season and was given the green light by coach Bruno Labbadia to leave before the end of his contract in June 2016.
Jiracek, who has been capped 28 times and scored crucial goals in the Euro 2012 finals which ensured they reached the last eight, previously played for another Bundesliga side Wolfsburg and Czech outfit Viktoria Plzen, with whom he won a league crown and a Czech Cup.