England kick-off their three-match tour in Wellington on Friday at 2pm (BST), with hooker Thacker and prop Rudkin starting together in the front row.
England Under 18
15 Zach Kibirige (Yarm School) (Newcastle Falcons)
14 Nathan Earle (Oaklands College) (Saracens)
13 Tom Stephenson (Moulton College) (Northampton Saints)
12 Nick Carpenter (Filton College) (Bristol Rugby)
11 Joshua Watkins (Bromsgrove School) (Worcester Warriors)
10 Billy Burns (Hartpury College) (Gloucester Rugby)
9 Callum Braley (Hartpury College) (Bristol Rugby)
1 Danny Hobbs-Awoyemi (Moulten College) (Northampton Saints)
2 Harry Thacker (Leicester Grammar) (Leicester Tigers)
3 Harry Rudkin (Wyggeston & Queen Elizabeth 1st) (Leicester Tigers)
4 Maro Itoje (Harrow School) (Saracens)
5 Charlie Ewels (Bryanston School) (Bath Rugby)
6 Ross Moriarty (Hartpury College) (Gloucester Rugby)
7 Gus Jones (Eton College) (London Wasps)
8 Joel Conlon (Ivybridge Community College) (Exeter Chiefs)
Replacements
16 Alex Lundberg (Hampton) (London Wasps)
17 Sam James (Bishops Stortford) (Saracens)
18 Biyi Alo (Haileybury College) (Saracens)
19 Jake Oldaker (Wellington College) (Bath Rugby)
20 David Hughes (Twyford C&E High School) (London Wasps)
21 Stephen Uren (Filton College) (Bristol Rugby)
22 Ollie Claxton (Adams Grammar School) (Unattached)
23 Sam Olver (Oudle School) (Northampton Saints)
24 Nick Tompkins (Oaklands College) (Saracens)
Tour itinerary
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