The Bluebirds are looking to bolster their attack and have shown
Niasse has found game time difficult to come by under the Portuguese tactician, having been limited to seven appearances this term.
"Strong interest coming from Cardiff but nothing is done yet," Silva said.
"We have to wait to see if the teams go this way or not but I can tell you the interest is strong.
"At this moment there is nothing more to say about that. Something could happen."
Cardiff City, one point and a place above the relegation zone are also believed to be interested in signing Nantes’ forward Emiliano Sala in their quest to avoid the drop at the end of the season.