Lipovac currently plays for BK Hacken in Sweden and West Ham have been impressed by his showings for the club this campaign.
Lipovac is now training with the Hammers' under-21 squad with his advisor Linus Jacobsson saying: "West Ham sent an official invitation to Hacken, who thought it was good timing and a good experience for Robert, so they released him for a week.
"He has just completed his second training session with West Ham U21 and stays until Sunday."
Lipovac is a centre-forward who has caught the eye in his homeland, but whether he will have what it takes to make it at West Ham remains to be seen.
If he does have the talent to break into the first-team it would be a major boost to Sam Allardyce, as they would not have to spend big on another forward.
The Hammers have had to recruit Andy Carroll, Diafra Sakho, Mauro Zarate and Enner Valencia to bolster their forward line in recent times and it shows just how much money could have been saved if they were producing their own talent.
West Ham's academy is highly reputed, but they have not managed to bring too many of their more promising youngsters into the senior squad of late and will want to make more of that production line in the coming years.