Manchester United have been drawn against Barcelona within the Europa League knockout round play-offs.
The stage of the competitors options eight runners-up from their Europa League teams, which incorporates United, taking part in the eight groups who have been third of their Champions League group.
The winners go into the last-16, which incorporates Arsenal after they topped their Europa League group.
United, who completed second behind Real Sociedad of their group, will be away for the primary leg.
Barcelona completed third behind Bayern Munich and Inter Milan of their Champions League group.