BELGRADE, Yugoslavia -- An easing of UN sanctions this week has Yugoslavia's top-flight basketball and soccer teams anticipating a triumphant return to the international sports scene.


But 28 months of tough trade and cultural embargoes have devastated Yugoslav sports so much that the eagerly awaited comeback could dissolve into disappointment for this sports-crazy nation.


Sanctions, lifted Wednesday, had been imposed on the truncated Yugoslav union of Serbia and tiny Montenegro as punishment for fomenting wars in the breakaway Yugoslav republics of Croatia and Bosnia. They are being eased to reward Serbia for cutting military support to Serb rebels in Bosnia.


The news triggered euphoria in Yugoslav sports circles. Soccer and basketball coaches have already unveiled new rosters and are planning strategies to crush their opponents.


"Now the world will see what it has missed,'' said Miljan Miljanic, manager of the national soccer team.


Yugoslavia was humiliated over being expelled from soccer's European Championships finals shortly after the sanctions were imposed in May 1992. Miljanic hopes Yugoslavia still can join the qualifying tournament for the European Championships in England in 1996, even though the draw has already been made and the first set of games played.


His newly announced roster includes such European stars as midfielders Dejan Savicevic of AC Milan, Vladimir Jugovic and Sinisa Mihajlovic of Sampdoria Genoa and several other players competing in the strong Italian, German and Spanish leagues.


Yugoslav clubs will have to wait until next year to join the various European cup competitions, which are already under way for this season. However, some of the best-known clubs, such as the 1991 Champions Cup winner Red Star Belgrade, have lost key players to foreign teams.


"The aging generation of Yugoslav sportsmen now competing abroad may prove too old for the international scene, and those youngsters competing locally are not at the world-class level,'' said Sergej Lukac, a university professor and sports expert.


Yugoslavia's basketball team, which has won European, world and Olympic titles, hopes to include Los Angeles Lakers center Vlade Divac. It also could tap the talents of guards Predrag Danilovic and Aleksandar Djordjevic, now playing in Italy, and forwards Zarko Paspalj and Zoran Savic, who are in Greece. But because the national team has missed the qualifying games for next year's European Championships in Greece, it probably will not be able to compete at the 1996 Olympics in Atlanta.


Vreme added that only "a miracle in the form of Bora Stankovic,'' the Yugoslav head of the World Basketball Federation, could "squeeze'' the team into the tournaments where they could face opponents such as wartime rival Croatia. "Can you imagine our match against Croatia?'' said Paspalj, a former NBA player. "It would be more than a game. It would be a war on the basketball court.''


Yugoslavia also could also field world-class water polo and men's and women's handball teams, providing a big boost for the tarnished national ego.