The round-of-16 tie is delicately poised after the 1-1 draw in the first leg in the Spanish capital.
The prize at stake is a place in the quarter-finals, with the draw due to take place on Friday, as United look to make it a night to remember under the lights at Old Trafford.
There were plenty of selection issues for Rangnick to ponder, with only Luke Shaw seemingly unavailable as he was already flagged as a doubt due to illness.
Bruno Fernandes is back after missing the superb 3-2 win over Tottenham, with Paul Pogba moving to the bench.