The forward scored three times at this summer’s competition in Brazil, alerting clubs in England and Portugal to his talents, and West Ham are keen to win the race to secure his services.
The Hammers have turned their attention to the 24 year old having had a £9.5m bid for Ukraine international Yehven Konoplyanka rejected by Dnipro Dnipropetrovsk.
Valencia scored eighteen goals in twenty-three league appearances for Mexican side Pachuca, having signed from Emelec in his home country the previous summer.
Internationally, his goals at the World Cup took his tally to seven in just thirteen senior appearances for the South American side.
West Ham finished in thirteenth place last season, and they begin the forthcoming campaign at home to Tottenham Hotspur, and they can be backed at 11/5 to take all three points.