The German Football League (DFL) has fined Union Berlin and two players over an impromtu party with fans in the club's stadium car park after their Bundesliga survival was confirmed in mid-week.

Late Friday, the DFL slapped fines on Union, club captain Christopher Trimmel and midfielder Sheraldo Becker after a group of players held a makeshift party with fans in the stadium car park following Tuesday's 1-0 home win over Paderborn.

A year after their promotion, the home victory, played behind closed doors due to the coronavirus pandemic, confirmed that Union will play a second season in Germany's top flight.

However, the DFL took a dim view of images of the players' party, which "had obviously violated general hygiene and infection protection standards", said the league a statement.

"This can be seen in video recordings that have been published on social networks, among others."

Several players, staff and Union coach Urs Fischer were involved, but the DFL singled out Trimmel and Becker, because of footage of them celebrating arm-in-arm with fans.

Both players were put into isolation until they returned two negative tests for COVID-19.

Trimmel captained Union at Hoffenheim in the league on Saturday with Becker left out of the match squad.