BILD says Blues owner Roman Abramovich personally tabled a €30 million bid for the newly capped Germany international.
"Yes, the interest was there," confirmed Sule's adviser Karlheinz Förster.
"The English have made it clear that their interest next season will remain valid."
Sule's father, Georg, says they won't be skipping out on Hoffenheim just yet.
"I think to go to a big club, you first must be a great player. Sure Niklas could earn more, but we do not look for quick money, but for a career. Niklas is developing well, the money will come later," said Sule Snr.