Janssen was yet to register his first goal for the North London club, despite coming close on a number of occasions, so when a penalty was awarded in the second half, regular taker Eriksen forewent his duties for the good of his teammate.
"I did think about taking it but I think I saw on Vincent's face and his body language that he really wanted it and you can feel for a striker," said Eriksen, who was on a hat-trick.
"And it is not as important for me with two or three goals. I was happy for him also and he did say thank you also, so it was a good one.
"He had a lot of shots in the first half and I think normally he would score. I think if you give him a penalty there is no better chance for a striker to score an easy goal."