The duo have spent time on the books of various European heavyweights, but they must prove their worth at United as the club looks to add to their forward clout
United are using just two of their international spots in their squad, but could increase their foreign contingent should either American Dexter Rosales or Portuguese forward Fabio Ferreira impress while training at the club.
Kosmina has Sergio van Dijk and Bruce Djite as his only two proven forwards ahead of the 2012-13 A-League season and the former has been linked with a return to his native Netherlands for family reasons.
But regardless of whether former A-League golden boot winner van Dijk remains with United or departs, Kosmina may elect to increase his options with either Rosales or Ferreira.
Rosales is a former US youth international who has spent time of the books of European giants Ajax and Valencia, but is out to prove he has fully recovered from a ruptured Achilles in 2011. The 25-year-old was linked with the Western Sydney Wanderers and can play anywhere across the front line.
Ferreira, meanwhile, spent time with the youth set-ups of both Sporting Lisbon and Chelsea, before returning to Portugal with lower-league sides Esmoriz and Sertanense.
He shifted to Australia in February to join New South Wales Super League club Dulwich Hill, where the 23-year-old has been among the goals. He, like Rosales, can play up front or on the wing.
"Their pedigree is good and we've got to cast the net far and wide, so they'll come here on trial and we'll have a look at them," Kosmina said via club statement.
United is hopeful that the duo will arrive in time to join the rest of the Reds squad for its pre-season training camp in Strathalbyn on Monday.