Juventus - Sporting is going to be a quite close matchup in my opinion. I don't see a big difference especially after Sporting eliminated the biggest favourite of the tournament which was Arsenal in last round.
This is making Sporting a pretty dangerous team actually. Arsenal were one of the best attacking teams in the Europa League. But Sporting still somehow resisted them in Emirates also and made it to this round by penalties. Juventus are going to be a more different opponent for them though. Juventus would play more cautious against Sporting which can make things more interesting in this matchup. It feels like Juventus can get a good result in Turin in the first leg. In that case Sporting's job would be quite difficult home.
Sporting made a huge football statement by eliminating Arsenal in the just concluded round 16 of UEFA Europa League and so it'll be a huge mistake by anyone to underate Sporting but that being said I'm still backing Juventus to oust them from the competition after the two legged encounter. Juventus fine form has been greatly superb especially after their scandal issues with Italian Football Federation and so they want to finish the season on a high note and winning the Europa League I think winning the competition will be one their current priorities especially now that they mathematically cannot win the tie