Hamburg have sacked boss Joe Zinnbauer and installed sporting director Peter Knabel as caretaker coach until the end of the season.
HSV suffered a 1-0 home defeat against Hertha Berlin on Friday and now sit 16th in the Bundesliga table -- the division's relegation playoff spot.
That loss led Hamburg to dismiss Zinnbauer on Sunday, with the coach leaving the club after only 23 games in charge.
The former Hamburg II boss was promoted three games into the season following Mirko Slomka's sacking, before going on to gain just 24 points during his tenure, while seeing his side score only 16 goals.
"The recent results and the overall situation forced us make changes," Hamburg CEO Dietmar Beiersdorfer told the club's official website.
Hamburg will now hope Knabel, who arrived at the Imtech Arena as sporting director in October 2014, can guide the club to safety.
"We are convinced that in our situation this is the best option for us. Peter knows the team and the circumstances," Beiersdorfer added.
Knabel last coached a team 15 years ago when he worked at FC Winterthur in Switzerland. Before joining Hamburg, he worked as technical director of the Switzerland national team from 2009.
On Monday, several news outlets reported that Hamburg hope to convince former Mainz coach Thomas Tuchel -- currently on a sabbatical -- to join the club in the summer. Hamburger Abendblatt claims that the 41-year-old did not rule out taking the job when he met the club met three weeks ago.