Gloucester Rugby's Billy Burns and Ross Moriarty have been selected as the reigning European champions head to the Rainbow Nation having already chalked up victories against Wales and France this season
However, Fletcher says that it will all be very different when the sides come together next month.
"We're really looking forward to it," he said. "It's been a while since we were last together but the lads are in good shape and we can't wait to get out there. Previous results count for very little, Wales are taking a different group of players and France will be tough, as ever.
"We know that we're going to have to play well and perform somewhere near our best to stand any chance of winning. But the aim is to play as well as we can, and if that means we win games, even better."
England's game against South Africa on August 18 promises to be another tough match, but again, one that Fletcher is hugely excited by.
"It's a tough, tough place to go and play rugby - as the seniors and the Under 20s proved this summer - they are a proud nation and they love their rugby. It's the third time we've been out there with the Under 18s and it's always a good test.
"A few years back we had the likes of Owen Farrell, Jonathan Joseph, Matt Kvesic and George Ford in with us, three years later and they're all in the senior set up - so the value of these tours and getting the guys together and playing the best rugby nations is massive."
England U18 v Wales U18 - August 10, Wellington
England U18 v France U18 - August 14, George
South Africa U18 v England U18 - August 18, Cape Town
Stephen Uren (Filton College) (Bristol Rugby)
Joel Conlon (Ivybridge Community College) (Exeter Chiefs)
Charlie Ewels (Bryanston School) (Bath Rugby)
Danny Hobbs-Awoyemi (Moulton College) (Northampton Saints)
David Hughes (Twyford C& E High School) (London Wasps)
Maro Itoje (Harrow School) (Saracens)
Sam James (Bishops Stortford) (Saracens)
Gus Jones (Eton College) (London Wasps)
Alex Lundberg (Hampton) (London Wasps)
Ross Moriarty (Hartpury College) (Gloucester)
Jake Oldaker (Wellington College) (Bath Rugby)
Harry Rudkin (Wyggeston & Queen Elizabeth 1st) (Leicester Tigers)
Harry Thacker (Leicester Grammar) (Leicester Tigers)
Biyi Alo (Haileybury College) (Saracens)
Callum Braley (Hartpury College) (Bristol Rugby)
Billy Burns (Hartpury College) (Gloucester Rugby)
Nick Carpenter (Filton College) (Bristol Rugby)
George Catchpole (Leicester Grammar) (Leicester Tigers)
Ollie Claxton (Bromsgrove School) (Unattached)
Nathan Earle (Oaklands) (Saracens)
Zach Kibirige (Yarm School) (Newcastle Falcons)
Sam Olver (Oundle School) (Northampton Saints)
Howard Packman (Moulton College) (Northampton Saints)
Tom Stephenson (Moulton College) (Northampton Saints)
Nick Tompkins (Oaklands) (Saracens)
Josh Watkins (Bromsgrove School) (Worcester Warriors)
Content courtesy of RFU