And hooker Ellis says confidence in the camp is high and he is counting down the seconds to his first ever international starting berth.
"It's been a lot of fun here so far," he said. "The travelling was hard but everyone's settled really well.
"We've got some really good training sessions under our belts and we're feeling pretty good.
"Obviously, I can't wait for my first start on Saturday. Unfortunately I didn't get a chance in the Under 20 RBS 6 Nations so this is my first chance to show everyone what I can do and I'm really buzzing off that.
"Argentina are well known as being some of the best scrummagers in the world. But we are really up for it.
"Shaun (Knight, Gloucester prop) and Joe (Marler, Harlequins prop) and myself have had a good look at them and we're confident we can do a job on them."
Ellis is joined in making his first start by Wasps wing Christian Wade, with Newcastle Falcons No.8 Alex Gray named as a replacement after returning from a broken rib.
London Irish's Tom Homer, the leading points-scorer with 68 points at last year's tournament in Japan, is named at full-back and his club teammate Marcus Watson keeps his place on the wing after solid performances in the last two games of the Under-20 RBS 6 Nations.
England squad to face Argentina
15 Tom Homer (London Irish)
14 Christian Wade (London Wasps)
13 Jonny May (Gloucester)
12 Tom Casson (Harlequins)
11 Marcus Watson (London Irish)
10 Freddie Burns (Gloucester)
9 Sam Harrison (Leicester Tigers)
1 Joe Marler (Harlequins)
2 Arthur Ellis (London Wasps)
3 Shaun Knight (Gloucester)
4 Calum Green (Leicester Tigers)
5 Charlie Matthews (Harlequins)
6 Will Welch (Newcastle Falcons)
7 Jacob Rowan (Leeds Carnegie, captain)
8 Jackson Wray (Saracens)
16 Jamie George (Saracens)
17 Lee Imiolek (Sale Sharks)
18 George Kruis (Saracens)
19 Alex Gray (Newcastle Falcons)
20 Charlie Davies (Stade Francais)
21 Rory Clegg (Harlequins)
22 Andrew Forsyth (Leicester Tigers)