Feyenoord have rejected Middlesbrough's bid for Lex Immers.
Sky Sports revealed on Friday that the 27-year-old was the subject of a bid from Boro.
Now Feyenoord have confirmed the offer, but they also revealed it was below their expectations.
"It was much too low, I do not take it seriously," said technical director Martin van Geel told NUsport.
Middlesbrough are still hoping to seal late deals on the transfer market and are in talks to land the likes of Danny Graham and Graham Dorrans.