Both West Ham and Newcastle have shown an interest, whilst Portuguese giants Porto are also said to be keen.
The Hammers even had a bid rejected earlier in the summer, but now they are reported to be reviving an interest - but the 21-year-old remains calm.
"It's fine to find out other clubs are interested in me. But my full focus is on Stuttgart," he told Sport-BILD weekly.
"I am under contract until June 2017 with the club and I do not force a move at this point in time. Of course, you never know in football. Still I am just focussed on my job and the new season.
"I have the best conditions to work at VfB Stuttgart, this will help me progress further. One day I want to come out for a big club in the Champions League. Anyway, this is still a long way off!"