Hamburg have told right-back Dennis Diekmeier to take their offer of a new deal or leave it and admit they could lose him if another club comes in with more money.
The highly-rated 23-year-old is only under contract with the Bundesliga club until the end of the season and there has been no agreement yet over an extension.
Reports have suggested that the former Werder Bremen youngster is demanding more from the club but Hamburg general manager Oliver Kreuzer is standing firm.
"Dennis Diekmeier has been handed a proper contract offer already, one that is good and well in line with those market requirements," Kreuzer told Bild.
"However, if there is a club that is able to offer Dennis the amounts of money he is still looking out for, we will be coming off second best in this."