Vivas suffered the injury whilst training with club side Internazionale, and will learn the extent of the damage on Tuesday.
With only a matter of months until the World Cup in Korea and Japan kicks off, Vivas could well miss out if the damage is as serious as first thought.
Inter and Argentina team-mate Javier Zanetti aditted that everyone is worried, and that to lose the diminutive defender would be 'very sad.'
"The incident happened when Vivas tackled a forward and his knee carried on moving," explained Zanetti.
"Let us hope that it is not so serious because it would be very sad for us all, but it is necessary to wait until Tuesday."
Vivas has battled hard to win over Argentina's impatient fans, and has established himself as an important player under coach Marcelo Bielsa.
Argentina have already lost the services of one important player Eduardo Berizzo, but have been boosted by the news that Diego Simeone could well be fit in time to travel to Korea & Japan.
