Schalke 04 have been strongly tipped with a move for the Brazilian, whose playing time this season has been limited to just 15 appearances in all competitions.
"Felipe Santana is a Borussia Dortmund player," Sky Sports News quotes Struth as saying.
"He has a contract to go beyond the end of the season. Of course, there are plenty of clubs with an interest in his services. However, we are not actually talking to any club about his future."
Santana has one goal in the Bundesliga this season.