Looking back on the 1-0 win which set up this week's encounter, Mark says:
"I loved it; it was my dream come true since being a little boy."
Nearly 17,000 fans enjoyed the game - the biggest crowd Mark has played in front of - and he adds:
"I had loads of nerves but they went as soon as I got on - then I enjoyed it.
"Once you come on and make a tackle or something like that the nerves go away and I was over the moon."
Mark, who came on for Teddy Sheringham - rested for this week's game - adds:
"I have achieved my dream and it is unbelievable; I was thinking of it when I was five years old.
"I think there are tens of thousands of West Ham fans who would like to have done what I have.
"I live five minutes from the ground, all my school friends support West Ham, and it just a wicked feeling knowing I have played for them.
"One of my friends had a bet on me to score the first goal and he lost his money - he is asking for it back!"
Unfortunately, that first goal is going to have to wait a little while longer, as he is still coming back from a minor problem which has ruled him out of the last fortnight.
"I had a little ankle injury but I was back training Monday so it is nothing too serious," he says.
As for his future, he says:
"I have to get my head down and work hard; if I am good enough it will come and if I am not it won't."
Since his debut, several players have come in to add to the competition, but he says:
"I am a West Ham supporter as well as a player and obviously I want us to go up - and we need the best players to make sure that happens.
"I will be patient and wait - hopefully - for my time to come."