Leicester Tigers centres Tuilagi, 19, and Twelvetrees, 22, are two of five new faces in the Saxons side. They will be joined by Harlequins prop Joe Marler, 20, Sale Sharks flanker James Gaskell, 20, and Northampton Saints lock Christian Day, 27. A sixth newcomer, Harlequins lock George Robson, is on the bench.
Head coach Stuart Lancaster has also selected two British & Irish Lions in hooker Lee Mears (Bath Rugby) and wing Ugo Monye (Harlequins) in a team captained by Harlequins flanker Chris Robshaw, one of seven in the starting line-up who have been capped at senior level.
The Saxons are out to sustain the momentum built up by five victories in 2010 when they face the Azzurri at Sixways on Saturday (3.15pm) before travelling to take on Ireland A in Belfast on Friday, February 4 (7.30pm).
“It’s an exciting group and we’ve got a bit of everything in the squad,” said Lancaster. “There are young players coming through, those getting their opportunities after showing great form in the Aviva Premiership and some who are older and more experienced who are keen to get back in the senior squad all of whom have added great value to the group.
“It’s been a short week to prepare to play Italy A but everyone’s bought into what we want to do and Worcester’s going to be a great place to play – a nice wide pitch and a passionate crowd – so it should be a great occasion.
“These players have got everything to play for in a World Cup year and they know it. It’s a big chance for all of them and it’s important for them to play for each other. If they do that, the collective performance will enable them to benefit from it as individuals.”
England Saxons (v Italy A, Sixways Stadium, Saturday, January 29, 3.15pm)
15 Mike Brown (Harlequins)
14 James Simpson-Daniel (Gloucester Rugby)
13 Manu Tuilagi (Leicester Tigers)
12 Billy Twelvetrees (Leicester Tigers)
11 Ugo Monye (Harlequins)
10 Stephen Myler (Northampton Saints)
9 Richard Wigglesworth (Saracens)
1 Joe Marler (Harlequins)
2 Lee Mears (Bath Rugby)
3 Alex Corbisiero (London Irish)
4 Graham Kitchener (Worcester Warriors)
5 Christian Day (Northampton Saints)
6 James Gaskell (Sale Sharks)
7 Chris Robshaw (Harlequins, captain)
8 Luke Narraway (Gloucester Rugby)
16 James Buckland (London Irish)
17 Duncan Bell (Bath Rugby)
18 George Robson (Harlequins)
19 Andrew Saull (Saracens)
20 Paul Hodgson (London Irish)
21 Brad Barritt (Saracens)
22 Olly Morgan (Gloucester Rugby)