The Hammers have been linked with a move for the former Manchester United hitman for the past month but they could once again miss out on a major target after reports from Mexico claim that their London rivals have begun to show interest.
But despite interest from the Blues, the bookies are still confident that West Ham will get a deal done for Hernandez.
Sky Bet have the Hammers as clear favourites for a deal at 4/6, while Chelsea are far out at 16/1. That figure leaves them behind both Man United (8/1) and even Tottenham Hotspur (14/1) who are yet to make a signing this year.
Chelsea have been linked with a whole host of striking options this summer – from Pierre-Emerick Aubameyang to Alvaro Morata – and it is believed that they are only interested in Chicarito as a back up to a big-money forward this summer.
Meanwhile, West Ham are expected to announce the loan signing of Joe Hart this weekend after agreeing a deal with his parent club Manchester City.
The England number one spent last season on loan at Serie A side Torino, and now he looks set to come to east London as Pep Guardiola does not see him in his future plans.
Where should Javier Hernandez go this summer? Let us know what you think in the comments below.