Let us start this by saying there is no way as of now to confirm the validity of the reports flying around the internet concerning this particular MLB rumor. Francys Romero, a BBWAA writer, and journalist is reporting that Yasiel Puig is close to signing a deal with the San Francisco Giants.
Romero has a heavy focus on the Cuban baseball community, so it makes sense that he would have the inside track to Puig rumors before most writers. As of now though, no other MLB writers have been able to remotely confirm.
Sources: Yasiel Puig is very close to sign with San Francisco Giants, a source tells me.