Werder Bremen coach Florian Kohfeldt insists they haven't been "knocked out" despite a first relegation for 40 years looming.

Werder were hammered 4-1 on Monday behind closed doors by Bayer Leverkusen, whose Germany forward Kai Havertz scored two goals to seal Bremen's seventh straight home defeat.

Bremen's glum home defeat completed the opening round of league matches as the Bundesliga became the first top European league to restart during the COVID-19 pandemic with rigid hygiene measures and fans locked out.

"There is still hope. This is not yet a KO blow for us," said Kohfeldt, who has nine games left to keep his side up.

However, four-time German champions Bremen, who last won the league in 2003-04, are firmly on the ropes.

After fellow former giants Hamburg were already relegated last season, north Germany neighbours Bremen are second from bottom, nine points from safety and five from the relegation play-off place.

They are now winless in their last 10 home games -- a club record in the Bundesliga -- and on course to be relegated for the first time since 1979-80.

Bremen have a game in hand, against mid-table Eintracht Frankfurt on June 3.

However, they will need a much improved performance to take any points from their next two opponents, Freiburg and Moenchengladbach, who are both in the top seven.

The Bremen defence could not handle Leverkusen's attack with midfielders Mitchell Weiser and Kerem Demirbay also scoring goals under little pressure.

"We were not good enough to take points," admitted captain and defender Niklas Moisander, with the 59 goals conceded by Bremen the worst in the league.