The pair were passed fit this morning, before the squad flew out to Germany for the showdown.
Johnson has sat out for three weeks with a hamstring strain, whilst Blanc picked up a knee injury when Leverkusen travelled to Manchster last week.
"Ronny Johnsen is back and everyone else is fit too," confirmed Sir Alex today.
United know they must go to Leverkusen and score goals to reach a dream Champions League final at Hampden Park.