Barcelona have conceded just six goals in this year's Champions League, with Marc-Andre ter Stegen being vital for the Catalans so far this season.
On their way to the quarter-finals, the Blaugrana have faced top-level teams such Inter, Tottenham Hotspur and Manchester United, and the German goalkeeper has managed to protect his goal on a handful of occasions.
In total, he has featured in 51 games in Europe's premier competition, conceded 46 goals and keeping 22 clean sheets.
Should he prevent United from scoring at the Camp Nou, Barcelona will qualify for the semi-finals of the Champions League.
Ernesto Valverde's side are aware of the dangers they could face in the competition, with their elimination against Roma last season helping to keep their feet on the ground and cause them to get carried away.