Thiago Silva  could leave Paris Saint-Germain  for Barcelona  this summer, his agent Paulo Tonietto has hinted.The defender, 28, has been nominated for Ligue 1 Player of the Year alongside two other Parisiens stars: Zlatan Ibrahimovic and Blaise Matuidi, following the club's Champions League quarter-finals exit to Barcelona and strong league showing where they are one win away from wrapping up their first title since 1994. However, rumours have surfaced that the former AC Milan star could be on his way out of PSG and his representative has poured fuel on to the fire by claiming the door is open for an unlikely switch."A transfer for Thiago Silva seems to me difficult - in his words - and I think that in the end he will remain at PSG. He has a contract and, before discussing with Barcelona, he should talk with PSG," he told RAC1."Last year we discussed [a transfer] with Barcelona but in the end PSG acted very quickly by offering a lot of money, [resulting in] an agreement with Milan. This year, however, we have not closed the door to Barcelona, nor to other clubs."The Brazil international has a contract at Parc des Princes until 2017, having joined from San Siro for €38 million last summer.