Hamburg manager Thorsten Fink says the club is desperate to hold on to striker Son Heung-min.
"We want to achieve something with Son," Fink told German Sky Sport News.
"I think it would be better for his sporting development, if he stayed and played with us.
"When anyone plays well, there is of course always a bit of transfer speculation about him.
"Ultimately, Son must know that we want to build something here and we have kept hold of players who want to also achieve something."