Well, he is a good player with good ability, IMHO. Can be very decisive, he scores sometimes. In the first season at Sporting, he was used also as striker and did well.
He is not very strong as a personality. He was injured some time, and made some pressure to have a place in the first team. That ended with a conflict with Paulo Bento, who left him outside the scheduled team for a while. Later on the trainer started to call him.
Now he is playing regularly in the first team.
Against Fiorentina, he scored the goal that led to a draw, but he took off his shirt to comemorate (he had already an yellow card) an was sent off. That had some influence in the final result (2-2 home draw for Sporting) and left him outside the second game.
In FM I just started playing Sporting and Vukcevic scored an hat-trick at the first friendly game, made a fantastic game with a lot of fantasy. He is good taking corners and free-kicks (much better than in real life).
But he is relatively irregular and his fitness is not the best to play the whole game so far.