The youngster is something of a football prodigy in his home country where he plays for Victoria and he has been handed a trial with West Ham.
The striker has flown to London with club chief Martin Fajardo, who is likely to stay with him during his trial at Upton Park.
Lacayo said: "I'm very hopeful of landing a move to West Ham. I could assure my family's future."
Hammers co-owner David Sullivan has indicated this week that there will be money to spend for the boss on new players to increase the size and quality of the club, although the signing of Lacayo would be more of one for the future.