The Guardian says the club's chief executive, Scott Duxbury, and technical director, Gianluca Nani, flew to Milan over the weekend with the intention of securing a deal with Internazionale for the 24-year-old.
Jiménez has been a bit-part player since signing for the Italian champions last summer and is keen to leave to find first-team football. The Serie A sides Fiorentina and Parma are also keen on the attacking midfielder but, having spent the bulk of his career in Italy, primarily at Ternana and on loan at Fiorentina and Lazio, he wants to move to another country and sees West Ham as an ideal location.
West Ham secured a work permit for Jiménez on Friday, having been instructed by their manager, Gianfranco Zola, to sign him before rival bidders had a chance to put a deal in place. The club hope to agree terms with both Inter and the player's representatives shortly. His medical could take place before the weekend.
Should all go to plan, West Ham will sign Jiménez - who has been capped 19 times by his country - on a season's loan in the hope of concluding a permanent deal next summer. The club expect to pay Inter in the region of £7m should they decide to keep him.