United travel to northwest Spain with the injury crisis easing and boosted by the return of several key men ahead of the semi final.
Paul Pogba and Juan Mata look set to feature, Marouane Fellaini is also available and defensive trio Eric Bailly, Chris Smalling and Phil Jones have all travelled with the squad.
Bailly's return in particular comes as a surprise having limped off early in the second half against Swansea clutching his knee.
Luke Shaw, however, has been ruled out for the rest season and joins long term absentees Marcos Rojo and Zlatan Ibrahimovic on the sidelines.
Celta took the La Liga scalp of Barcelona back in October but have had an inconsistent league season.
Eduardo Berizzo's heavily rotated side went down 3-0 to Bilbao last time out and they come into this first ever competitive meeting with United in a comfortable mid table position.
Celta's top scorer, former Liverpool misfit Iago Aspas, was among those rested in readiness for this one but ex Red Giuseppe Rossi - who now plies his trade for the Celestes - is injured.
United, by contrast, are unbeaten in 11 matches and on a club record run of 25 games without defeat, although 14 of those have ended in frustrating stalemate.
A historic place in the final (and a Champions League place) awaits the winners, with the Reds bidding to win the only major trophy missing from the club's trophy cabinet.
The showpiece will be played in the Swedish capital Stockholm on Wednesday 24 May.
Eredivisie giants Ajax look to have one foot in the final having stormed into a commanding 4-1 lead over tournament favourites Lyon in Amsterdam on Wednesday.
United manager Jose Mourinho said: "I know that it is the only competition that Manchester United as a club has never won.
"It would be great to close the circle and say 'we are a club that has won every single tournament in football.
"This is a difficult tie for us, because of their situation in the league, a comfortable one, they managed to think only about this game and rest players to be in the maximum condition.
"We have not been able to do that so the advantage is there for them, they have a strong identity and I am expecting another difficult match."
Form guide: Celta Vigo W W D L L L United D W W W D D
Match odds: Celta Vigo 12/5 Draw 9/4 United 13/10
Referee: Sergei Karasev (Russia)