The summer signing from FC Utrecht said "On my first day at Portsmouth I was told by a fan that if we won only one match all season it had to be against Southampton. This is how much it means.
"It has been difficult time for me so far. I have let in eight goals in four matches but I do not think I have done anything wrong.
"I let in two against Leicester on Saturday but they were unavoidable. Even so, the pressure is on me. This would be a great time to improve my own form."
Wapenaar is familiar with the Carling Cup - two of his four apperances have come in this competition - in the 5-2 win over Northampton and the 4-2 victory at Notts Forest.