Thorsten Fink has admitted that Hamburg may have no choice but to sell Son Heung-min at the end of the season.
Highly-rated striker Son has reportedly attracted interest from several top clubs, including Arsenal and Tottenham in the Premier League, and Hamburg general manager Frank Arnesen revealed earlier this week he could leave this summer if he does not sign a new deal.
Son's current contract expires in June 2014 but Hamburg are rumoured to be struggling financially and head coach Fink recognises they may have to cash in on the 20-year-old South Korean.
He told Sport-BILD weekly: "If Heung-min Son is not signing a new contract and makes up his mind to definitely leave, and given a concrete offer from an interested club, then we would be forced to sell.
"In a situation like this we would be unable to do anything else as we would be unable to keep hold of him."