Manchester United midfielder Ander Herrera has described Europa League opponents Celta Vigo as a "very complicated team".
United are favourites to reach the final of the competition after being drawn with a club who are only in mid-table in La Liga, but Herrera has warned his teammates to not take the Spanish side lightly when they play the first leg on Thursday night.
The 27-year-old told The Mirror: "Celta are a very complicated team, with players that have a lot of quality.
"In theory, we are the strongest team left in the competition but we have to respect all of our rivals because otherwise, they can surprise us."
United may need to win the competition in order to qualify for next season's Champions League.
