The now ex-Wigan man says that despite a long season, he and his teammates are feeling fresh.
“World Cups don’t come around too often so we are all buzzing and full of energy,” said Mossop.
“The sports science staff are keeping us all fresh, and if you are not up for a semi-final I would say there is something up with you.”
At this stage of the 2008 tournament the Kiwis knocked England out with a 32-22 victory, and Mossop is all to aware of the threat they pose.
He said, “For me New Zealand are the best team in the competition this year. I think the way they are playing, the points they have got on the board and the individual brilliance they have got is showing every week.
“You can’t concentrate on them too much though, because if you do that then you won’t do your own job correctly. You have to do your bit right first.”
The 20-year-old, who has scored six tries in the tournament so far, feels he is improving even more due to his involvement with the New Zealand squad.
He said, “There is so much to learn from all of the big boys and we have a very good forward pack so that also makes a difference.
“I am the youngest in the camp and there are a lot of guys here that have so much experience for me to use to get better. Each day I just make sure that I am talking to them and picking up on anything that I can.
“Manu Vatuvei is someone that I really look up to and we feed off each other’s ability, it is just so surreal that I’m playing with guys like him because he was my idol growing up.”
Unfortunately for Tuivasa-Sheck, Vatuvei is unavailable on Saturday due to a groin injury and he is replaced in the matchday 19 by Alex Glenn.
New Zealand: Jesse Bromwich (Melbourne Storm), Kieran Foran (Manly-Warringah Sea Eagles), Alex Glenn (Brisbane Broncos), Bryson Goodwin (South Sydney Rabbitohs), Shaun Johnson (New Zealand Warriors), Sam Kasiano (Canterbury-Bankstown Bulldogs), Kevin Locke (New Zealand Warriors), Issac Luke (South Sydney Rabbitohs), Simon Mannering (New Zealand Warriors), Ben Matulino (New Zealand Warriors), Sam Moa (Sydney Roosters), Jason Nightingale (St George Illawarra Dragons), Frank-Paul Nuuausala (Sydney Roosters), Frank Pritchard (Canterbury-Bankstown Bulldogs), Elijah Taylor (New Zealand Warriors), Roger Tuivasa-Sheck (Sydney Roosters), Jared Waerea-Hargreaves (Sydney Roosters), Dean Whare (Penrith Panthers), Sonny Bill Williams (Sydney Roosters).
England: Carl Abblett (Leeds Rhinos), George Burgess (South Sydney Rabbitohs), Sam Burgess (South Sydney Rabbitohs), Rob Burrow (Leeds Rhinos), Josh Charnley (Wigan Warriors), Leroy Cudjoe (Huddersfield Giants), Liam Farrell (Wigan Warriors), Brett Ferres (Huddersfield Giants), James Graham (Canterbury-Bankstown Bulldogs), Ryan Hall (Leeds Rhinos), Chris Hill (Warrington Wolves), Lee Mossop (Wigan Warriors), Sean O’Loughlin (Wigan Warriors), James Roby (St Helens), Kevin Sinfield (Leeds Rhinos), Sam Tomkins (Wigan Warriors), Kallum Watkins (Leeds Rhinos), Ben Westwood (Warrington Wolves), Gareth Widdop (Melbourne Storm).