I know that Sporting surprised everyone by pushing Arsenal out of the Europa League in the previous stage. Arsenal were the biggest candidate to win the title in the end. It was a really difficult task for Sporting. Especially after seeing how Arsenal played in Portugal and got a decent result I thought that Arsenal would finish the job in Emirates. But Sporting did the unexpected and eliminated them by penalties. After this result I guess the fans will be more expectant from Sporting.
I wasn't surprised when Arsenal lost to Sporting. in particular, in the second leg. if, at that time Arsenal played the main full starter. I'm pretty sure, they will have no trouble holding a draw until the penalty shoot-out. plus, two pillars of their defense were injured early in the game. but after all, Sporting was able to subvert Arsenal. also, what they display quite impressed me. moreover, they play appear all out.
on the other hand, I can understand Arsenal's defeat in that match. As an Arsenal fan, I'm not too disappointed. because, Arteta is more concerned with focusing on the Premier League.
However I still see Juventus as the favourite side of their matchup against Sporting. Juventus are a different team than Arsenal. Their strategies might cause Sporting to have bigger problems maybe who knows. It is all up to Juventus' having the matchup under control mostly. As long as Sporting don't take control of it I don't think they can make it to the next stage.
Rigth, even though Juventus did not show a great performance. however, we can not look at it one eye. because after all, Juventus is a strong team in this competition and is more favorite when compared to Sporting. but I won't assume too far, besides this match still has a time lag, we can't say for sure what the two coaches from each of these teams will do later. however, I have special concern for Juventus. if they are able to easily subvert Sporting smoothly, then Juve has the right to be one of the challengers who will advance to the final.