A match that is difficult to predict, because with an aggregate of 1 goal, Sporting can still really chase after them, especially since they are superior because they are playing as the host in this match. It looks like the result of this match is still 50:50 because in the first leg Sporting was able to keep pace with Juventus' game. I wouldn't be surprised when Juventus had to be eliminated in this round, as Arsenal felt when they met Sporting.
Sporting still has hope to turn things around in the second leg because they host the second leg. Sporting can take advantage of the weaknesses of the opposing team which is currently not in the best condition after losing 2 matches in Serie A. Their chances are still 50:50 and for Juventus they may be a little confident because they have the winning capital from the first leg which they must make the best use of maybe for the second leg.
Juventus still have problems on the front lines because their stickers have lost their sharpness to score goals. For Sporting they can do extraordinary things if they are able to repeat the more aggressive form of play they used to beat arsenal. I'm sure the second leg will be full of drama and maybe extra time will put them in the penalty spot.
I think it is possible, if you are good enough to beat Arsenal, then you are good enough to beat Juventus as well, it is all possible. However, I do not really see that as the likely thing, being possible and being the likely outcome is not the same thing. It is possible for Lisbon to win, but it is likely that Juventus will win this game too, they are just too good these days and they are looking to take that cup.
I hope that they do what they set out to do and get the europa cup so they would be at champions league next season. They are fighting on court right now for their future, but if they are in UCL then that means nobody from Serie A federation can do anything about that and they will be getting a ton of money as well.