Son has extended his contract with the club until 2014, while Besic’s new deal will keep him at the club until 2013.
Stepanek has extended his contract with Hamburg until the summer of 2012.
“Our sporting philosophy at Hamburg is to have young, hungry and talented players at the club in the future. We have begun that today by handing this contract-extension to these three players,” sporting director Bastian Reinhardt told the club’s official website.
“All three, but especially Son and Besic, have shown their potential from the beginning of this season.”