Hoffenheim supporters mocked banned goalkeeper Tim Wiese during the weekend's 3-0 win at bottom-of-the-table Greuther Furth.
Wiese, 31, lost his spot between the Hoffenheim posts when the club brought Tottenham's Heurelho Gomes in on loan on the final day of the January transfer window.
Last week, the former Germany international was banned from the squad after he was allegedly out drinking beyond midnight at a handball match. He denied the accusation and said he had "only had one or two beers".
On Saturday, travelling Hoffenheim fans mocked him with a banner reading: "Tim, join us for an away trip - we take care of the booze."
On Sunday, Wiese, under contract at the club until 2016, told Bild: "Wicked banner, wicked fans." Kicker reported that the 'keeper could soon move to an MLS club.
Hoffenheim officials played down the incident. "We should not give this too much importance," boss Marco Kurz said. "We should focus on the game."
Skipper Andreas Beck said "malice and sarcasm" were never good, adding: "It is not easy for him [Wiese], but he has to go through that now." The club's president Peter Hofmann condemned the banner as being in bad taste.
The victory at Furth, who have not won in 13 home games this season, gave struggling Hoffenheim fresh hope as they cut the gap to Augsburg, in the relegation play-off place, to two points.
"The key to our victory was not only our performance but also the great support from our fans," Kurz said.