After making his first senior appearance in an Ulster jersey as a substitute against La Rochelle in the Stade-Marcel Deflandre, Sheridan was rewarded for a combative display with his first Ulster start last week.
It was a huge show of faith in the 21 year old, as Ulster's chances of progressing in the Heineken Champions Cup depended on winning.
Now he is looking forward to tonight's test, a vital URC match against the reigning champions.
Tickets for tonight's match can be found here:
Sherdian says that the side can expect a big test against the South Africans.
"We will be ready for it, it's a big challenge and their squad will want to light it up but we will get stuck into them. Hopefully we will have an atmosphere like last weekend. In training in this week we've been working on our power game and working on our accuracy."
Sheridan says that the last few weeks have been a dream for him as a lifelong fan and that his experience away to the reigning European champions (La Rochelle) was an eye-opener.
"Growing up in Ulster, my Season Ticket is at the grandstand so, I've always been a fan watching the boys. When i came out of school I wasn't really being picked at under 18 level and I had lost a bit of faith. I managed to turn it around for under 19 and I'm not taking anything for granted.
"Against La Rochelle I had never experienced anything like it, being on the bench was deafening. The senior boys helped me with trying to enjoy the moment. "
Cherishing the moment
Dan McFarland saw enough in his performance to start him in the crucial game against Sale Sharks last weekend and Sheridan says it was an unexpected start but that he was able to savour the moment with family and friends.
"It is quite hard to describe. Initially it's overwhelming but I appreciate the work I’ve done to get here to sit in the number 6 chair in the locker room and I had to quench the nerves . It thankfully went well.
"When I got subbed off , I took my time and looked up. My friends were in the Family Stand and I saw my grandad in the grandstand. I've gotten to the stage where I want to keep building. I savoured the moment that night."
Sheridan says his grandfather is a man of few words and simply told him after the match "Well done, Harry."
Kingspan Stadium memories
"I remember being in the top right of the Grandstand with my family when I was younger. There was still grass over at the Family Stand and I remember the players wearing red and white socks. It’s a bit different being on the pitch than being in the stands!"
Student life
Currently enrolled as a student at Trinity College in Dublin, Sheridan is balancing his time between the books and a promising rugby career.
"Suddenly one week I need to stay on top of work. In one week you might have six classes and you need to give them the attention, then you have to go play a match.
"I had to miss an exam at Christmas because I was selected for an Ulster A match - it's strange telling the tutor that i have to miss this because of my career prospects in rugby!"