Scharner left West Bromwich Albion during the summer to move to Germany but he has failed to hold down a regular place in Hamburger SV's starting lineup.
It has been reported that Sunderland have made an offer for the Austrian international and Scharner has admitted that he expects a formal offer in the next few days.
Scharner told the Hamburger Morgenpost: "There is yet again an interest in my services from a club in the Premiership.
"I expect them to put this in concrete terms in the next couple of days."
The 32-year-old has played less than an hour of Bundesliga football this season.