Sky Sports reports how the Asian star has attracted interest from a host of clubs across Europe after a series of scintillating performances in the Bundesliga this season.
Son first arrived in Germany at the tender age of 16, when he joined Hamburg's youth academy, and has gone on to establish himself as an integral part of Thorsten Fink's first-team.
Red Devils boss Sir Alex Ferguson is believed to be monitoring the 20-year-old's situation, with a view to making a bid to bring him to Old Trafford in the future, while Premier League rivals Chelsea are also thought to be courting the talented youngster's signature, as Roman Abramovich continues his quest to bring the brightest up and coming talent to Stamford Bridge.
However, both Chelsea and Manchester United will face competition in their ongoing fight to secure Son's services, with Serie 'A' giants Inter Milan a third confirmed European suitor.
"Inter Milan's emissaries saw a couple of his matches, but so far I have not had any contact with the Italian club's officials," Bliemeister told Interlive.
"A transfer in the next summer? He has signed a new contract with Hamburg SV extending it for one year, but there have been many offers for him from Manchester United and Chelsea."
Son has scored nine goals for Hamburg this season, and it was reported earlier this week that it will take a bid in the region of £10million to activate negotiations with the player directly over a possible transfer.