The inside centre has recovered from the concussion sustained playing for London club Saracens that threatened to rule him out of a match that pits England against one of their pool opponents at next year's World Cup in France.
Farrell takes over from Courtney Lawes, whose involvement in the Autumn Nations campaign is threatened by his own concussion problem.
When naming his squad last month, England coach Eddie Jones said he had made Lawes captain instead of Farrell because of the Northampton back-row's greater composure when talking to referees - a key aspect of the modern game as the penalty count can often be the difference between winning and losing.
Farrell is often a fiery figure on the field, his passionate approach making him appear confrontational, but he is determined to remain true to himself while evolving his leadership style.
'Be a better me'
"I'd say the challenge for me is obviously the way that I play the game, the way I present myself at times when I'm playing," said Farrell, who last skippered England against Australia a year ago.
"It's not always necessarily what I say, it is sometimes making sure that you're giving off the right message as well," added Farrell, England's captain in their 2019 World Cup final loss to South Africa in Japan.
"There are different captains all over the world. There have been really, really calm ones that are good.
"And there's been some explosive ones that have been really good as well. There are still a few of those knocking about now. I want to be me and I want to work on how I be a better me."
For Sunday's match Jones deploys his preferred midfield trio of fly-half Marcus Smith, Farrell and the dynamic Manu Tuilagi for the first time following injuries to the two centres.
"Manu has got certain qualities which no other centre in England has got," said Jones. "He's got power, he can run a line, he can carry defenders with him and he can create quick ball."
Sunday's match is the first of four games as England also face Japan, New Zealand and South Africa on successive weekends at Twickenham.
There was a time when England would have been overwhelming favourites to beat both the Pumas and the Cherry Blossoms.
But Argentina won away to the All Blacks during the recent Rugby Championship and Japan ran New Zealand close in a 38-31 defeat in Tokyo last Saturday.
"Every game is dangerous," said Jones, the former Japan coach. "New Zealand went to Japan and they thought they would eat nice sushi, drink sake and have a nice runaround on the national stadium - and they nearly came unstuck.
"That is the fantastic thing about rugby at the moment...you look at the state of world rugby and the potential upsets there are.
"We just treat them (Argentina) as a highly respected opponent. We have given them 100 percent diligence in preparing. Is it dangerous? Every game is dangerous."
