The German has been starring at right-back for the Serie B club after arriving on a free transfer from Schalke last summer.
Calciomercato.com claim Watford, Werder Bremen, Sampdoria and Udinese are interested in the 23-year-old.
And, given that the two clubs share scouting and recruitment information, it is no surprise to see Watford and Udinese both among the player’s suitors.
The Hornets are not badly off at right-back now that Kiko Femenia is back to full fitness with Javi Gracia having introduced him on the wing ahead of starter Daryl Janmaat against Everton recently.
Newcastle have been linked with a shock move for former Sunderland goalkeeper Simon Mignolet during the summer.