Speaking ahead of Thursday's clash, AS Roma manager Paulo Fonseca said: "This semi-final with Manchester United is very important and I must stay entirely focused on a game that is too important for us.
"It's true that Man United are very dangerous on the counter-attack, but we must realise it'll be really difficult if we go to Manchester and just defend.
"We need to keep the ball and make it difficult for them. The team must show character and not sit too deep."
Roma suffered a surprising 3-2 defeat against Cagliari in the Serie A on Sunday although Fonseca opted to rest several key players ahead of the Europa League semi-final tie.
Should the Red Devils go past the Italian side, they will face either Arsenal or La Liga team Villarreal in the final in Gdasnk on May 26.
