If he wanted to, he could play here now, but he keeps extending, so why bother? PSG won't let him leave before his contract end, and he has been persuaded by money many times before..
If he leaves or not is not up to him and his agent, that is for sure.
Silva signed in 2012 and extended in august 2013 (1 year until 2018) and december 2016 (2 years until 2020). I believe we were after him in the summer of 2013, when we ended up with Song, because we had no alternative and he ended up extending his 5 YEARS contract. 
Verratti: Signs in 2012 until 2017 (5 year contact). Extends august 2013 until 2018. Extends September 2014 until 2019. Extends February 2016 until 2020. Extends August 2016 until 2021. But yeah, tell me about how much he wants to move. 
There is a pretty convincing pattern with PSG, that their best players always extend or runs down their contracts if they want to leave without the club approving (like Zlatan). Marquinhos, Silva and Verratti has always been hopeless dreams.