Here's our storylines, how you can watch the match and more:
How to watch and odds
Date: Thursday, Mar. 16 | Time: 12:45 p.m. ET
Location: Estadio Benito Villamarin -- Seville, Spain
TV and live stream: WATCH FREE HERE
Odds: Betis +250; Draw: +250; United +105
Team news Betis: Luiz Felipe is expected to be missing until after the international break after playing through pain last week so expect Victor Ruiz to start. Nabil Fekir is out long-term after his season-ending injury and Juan Cruz will also miss out. William Carvalho is back from a domestic ban and Sergio Canales could push 41-year-old Joaquin onto the bench.
United: Casemiro should feature given that he will be suspended for four domestic games but Ten Hag knows that he is without the injured Donny van de Beek, Christian Eriksen and Alejandro Garnacho. Victor Lindelof and Marcel Sabitzer are both doubts too although Anthony Martial could get some valuable minutes as he continues to step up his comeback bid.
Prediction This one was close until United pulled away in the second half and it should be similar here. Betis are unlikely to have the quality to win, but they can certainly hold United on home soil. Even a three-goal win would only take this beyond 90 so it is difficult to see the Spaniards advancing. PICK: Betis 1, United 1 (2-5 on aggregate).
