Farrell wants his players to deliver a performance which proves they are ready to go toe-to-toe with the best in the world.
The buzz-phrase in the England camp this week has been that this QBE autumn series is "production time", that the brutal lessons learned in South Africa over the summer must now be put into practice.
The world's top three nations - Australia, the Springboks and world champions New Zealand - are all due at Twickenham over the next month.
And Farrell wants England to set the tone right from the off by dispatching Fiji and delivering on the growing expectations of the 82,000 sell-out crowd.
"We have to be ruthless and show them no mercy," he said after England's final training run at Twickenham.
"We are after a performance. We feel like we have got the foundations in place and now we are ready to put some layers on top.
"We have to make sure we set the same level as far as intensity, passion and fight - but the boys also understand that they have to kick on.
"To be the best and beat the best, there is an extra 15 to 20 per cent there.
"We are six months into our journey and there has to be improvement. It is about us kicking on to the next level.
"We are aware of what is coming and it doesn't really get any more exciting than the challenge in front of us over the next month."
The very fact that 82,000 will cram into Twickenham on Saturday indicates the growing expectation surrounding Stuart Lancaster's England team.
The last time England played a Test at home they demolished Ireland 30-9 to finish second in the RBS 6 Nations before embarking on their bruising trip to South Africa.
Lancaster's young squad returned with two defeats and a 14-14 draw but with eyes opened to the intensity and execution required to be the very best.
England were beaten up in the first two but they learned quickly and are still kicking themselves for not winning in Port Elizabeth.
But it has left England confident they can deliver against the big three, which is why Lancaster, Farrell and the players have embraced the rising sense of expectation.
"It brings a different type of pressure. It is when people are expecting something that you want to go perform. That's what we want to do as players," said captain Chris Robshaw.
"We are under no illusions how dangerous Fiji can be. We have to be ruthless. We have to take every opportunity we can and not take 15 minutes to get into the game, like we did in South Africa.
"We have to deliver from minute one."
England are fielding their most inexperienced side for a decade, with Robshaw one of 11 players in the greenhorn starting line-up boasting 13 caps or fewer.
Tom Youngs will make his Test debut at hooker in place of the injured Dylan Hartley, just three years after moving to the front row from inside centre.
"I'm very excited to see him play," said Farrell.
"I played against him when he was at 12. He was hard to play against then. He's a real bowling ball and he adds an extra dynamic to our team."
Prop Joe Marler, full-back Alex Goode and blindside flanker Tom Johnson all continue in the side that drew in Port Elizabeth and will make their first Test appearances at Twickenham.
Jonathan Joseph's ankle injury made Lancaster's midfield decision easy, with Brad Barritt linking up in a heavy-duty partnership with Manu Tuilagi.
Goode will offer England a second ball-playing option from full-back, a tactic used with some success by New Zealand during their Rugby Championship title campaign.
Charlie Sharples takes over from the suspended Chris Ashton on the right wing while Ugo Monye returns to England action on the left for the first time since March 2010.
England's most experienced unit are the half-backs, with Toby Flood and Danny Care - man of the match in Port Elizabeth - contributing 83 caps to the combined total of 215.
Lancaster's plan is that the bulk of this England squad will be around at the 2015 Rugby World Cup, wiser still and far more experienced.
England must retain their fourth-place ranking through this autumn campaign to ensure they are top seeds for the tournament, when the pool allocation draw is made on December 3 in London.
And in that World Cup context, tackling Fiji, Australia, South Africa and New Zealand on successive weekends is probably tougher than anything England would have to overcome to win the Webb Ellis trophy.
"That is something we've talked about as a coaching staff and as a team," Farrell said.
"The more dress rehearsals you can have, the better."
Gilbert has released a new line of rugby cleats. The Gilbert Virtuo 8S is part of the exciting new product. Check it out.
The entire All Blacks apparel line has been updated for 2013/14. Check out the New Zealand All Blacks polo.
The Nike Tiempo is a solid rugby cleat and one of few styles still made from full-grain natural leather.
The Gilbert Blitz 8S rugby cleat is a great cleat at a great price of $69.99. Get a new pair of cleats today.
A cool looking all black rugby cleat with the high performance adidas is known for. Get in the Gear!
Wear the crest of the British and Irish Lions on your t-shirt. A great look for the summer.
The All Blacks Performance t-shirt is black with hints of blue from the training jersey. Very Cool.
The New Zealand All Blacks training jersey for 2013/14. Get in the Gear!
The USA Rugby Pro Alternate rugby jersey is perfect for any fan of the Eagles. Get yours to wear during the summer Test matches.
The NEW All Blacks 2013/14 jersey has arrived at World Rugby Shop. Dare to wear the colors of the All Blacks.