Dutch defender is confident of setting up a semi-final date at Wembley with Merseyside rivals, Liverpool, despite being held by the Black Cats at Goodison Park on Saturday
Heitinga told Everton's official website: “Of course we still believe we can go through.
“We're still in the cup. Now we need to play 90 minutes over there and maybe extra time. But we will do everything to win over there and continue in the cup.
“It will be difficult. They play at home so they'll have the home crowd. But I'm sure the away end will be packed with Everton fans and they can make a lot of noise.”The Dutchman believes that the Toffees deserved to win the initial tie at Goodison Park but is happy that his side are still in the competition after Tim Cahill cancelled out Phil Bardsley's fantastic opener.
Heitinga said: “We’re disappointed because we played at home, we conceded an early goal because we didn't start very well. But after that I think there was only one team who deserved to win.
“You come out of the dressing room with one thing in mind and that's to win the game. When you lose an early goal, you know you need to score an equaliser. We did that before half time and in the second half, we were the only team that played football. They were standing with 11 men in their own half.
“But in the end it was 1-1 and we have to be happy we’re still in the cup. Now we need to win over there.”