Fulham are understood to have made a £1.6m bid for Vitesse Arnhem full-back Alexander Buttner.
The 23-year-old, who is out of contract next summer, has also been linked with moves to Werder Bremen and Shakhtar Donetsk.
However, he is believed to have travelled to London earlier this week to be shown around the Premier League club, according to De Gelderlander.
Buttner has made over 100 appearances for Vitesse after graduating from their youth academy in 2008.