Luis Enrique’s men have one foot in the final after their 2-1 victory in the Spanish capital last week.
Luis Suarez and Lionel Messi put Barca 2-0 up on the night as they appeared to be cruising into the final.
But Antoine Griezmann gave Atleti hope ahead of the second leg at the Nou Camp.
They have a decent record at the Nou Camp too, with the two sides playing out a 1-1 draw earlier in the season.
Celta Vigo or Alaves await and the winner of this one will be confident of winning the competition.
Who will secure their spot in the Copa del Rey final?
Barcelona:Cillessen, Roberto, Pique, Umtiti, Alba, Rakitic, Gomes, Denis, Turan, Messi, Suarez.
Atletico Madrid:Moya, Juanfran, Savic, Godin, Filipe, Koke, Saul, Gaitan, Carrasco, Griezmann, Torres