I thought that this was absurd when I first heard the rumour. Now though, I'm not so sure.
When Jardim was at Monaco before, he wasn't very happy with Tielemans. So, it wouldn't be a surprise to see him want him out now he's gone back.
The rumour at the moment (reported in France) is that the talks are over an exchange with Silva (who was Jardim's player at Sporting Lisbon). Again, that would make some sense.
Tielemans is a proper wonderkid. Exceptionally talented but quite possibly has disappeared up his own reputation. His attitude is under question. However, his talent is undoubted. There is no way we'd be a possible option for him unless his stock had recently dropped sharply.
21 though, seasoned pro in the Belgium squad and in Champions League games. Capable of being a superstar. Could be a shambles too mind. Plenty of wonderkids turn to shit.
However, a swap for Silva is not a great risk. We're hardly getting anything from him at the moment.