The main problem with Juventus is their position in Serie A the team is playing well in both Europa League and Serie A. But, I guess they will have a hard game against Sporting because this team won the game against Arsenal in the last stage Sproting doesn't have valuable and expensive players in the team yet but they have still shown us a good performance in the recent games and if Juventus don't want to get surprised they should be careful in the next game against Sporting.
Sporting proved something great against Arsenal but I think they were just lucky at the penalty stage. Meanwhile against Juventus, I think Sporting just won't be the favourites.
I may have underestimated Sporting at this stage as I tend to believe Juventus are the better team. Another problem is, Juventus is not the team most likely to win the Europa League title based on history, but that is in the past. Looking forward to this fight in mid-April. Some of the teams that will advance to the semifinals are Roma, Juventus, Sevilla and Leverkusen. I doubt Manchester United, but they are also good to hope for.