Looking forward to the Dubai tournament, which runs between March 5 and 7, the Ulster scrum half said: "We're really excited about the World Cup. It's a really talented squad we're taking away.
"Looking across the board, I don't think there's anyone that knows whether they're definitely going to be playing or not at the minute.
"This weekend's warm-up tournament in Portugal will be important because we haven't played any matches recently.
"It will give us a couple of games and also everybody's in the shop window for the coaches to see before Dubai.
"We're maybe not as well known as other teams but to me that'll be an advantage for us in the World Cup because they'll not know what we're about, who to watch out for, who the key players are and hopefully we can catch a few of them by surprise."
Marshall is one of the newer players introduced into the Ireland Sevens set-up, with the panel backboned by team captain Kieran Campbell, James Coughlan and Brian Tuohy who all featured during last year's qualification tournaments.
"I'm only really in the squad the last few weeks. I didn't play in any of the previous tournaments," he explained.
"The experienced guys have been great, explaining things to us about how we want to attack or how we want to defence.
"Certainly one thing I've noticed from the experienced players...they really want to keep the communication levels high. That's been a real incentive for me to talk more and for everybody else to talk more.
"There are only going to be a few of us on the pitch at one time and we've got to make sure we communicate and we know what's going on with each other.
"There's a great atmosphere in the squad, a very good bond already and the guys have been getting on really well."