Red Bull has been weakened, and Ferrari and McLaren strengthened, by F1's latest personnel moves.
That is the claim of Mercedes boss Ross Brawn, who said the dominant champions will miss the input of aerodynamics chief Peter Prodromou, who has been signed by McLaren.
"I don't think any team can lose someone of that experience and calibre without it having some impact," Brawn is quoted by the Guardian.
Another move that will have an impact, Brawn added, is James Allison's switch from Lotus to Ferrari.
"James Allison has gone from Lotus having designed a very good car there, to Ferrari, and I am sure next year their car will be a lot better," he said.
"That's the nature of the business.
"It happens in F1 all the time. Red Bull are where they are because they took Adrian (Newey) out of McLaren. It's the nature of F1."
Meanwhile, Brawn defended Mercedes' Lewis Hamilton, after the British driver made bad-tempered and contradictory radio calls to his engineer in Austin.
When told to look after his tyres, the 2008 world champion hit back during the US grand prix: "That's what I'm doing man, let me focus."
But after the ensuing radio silence, Hamilton later insisted: "You need to give me some feedback, man -- tyres, temperatures."
When asked about Hamilton's inconsistency, Brawn said: "We are just getting used to working with Lewis. It's not problematic."
Hamilton said he had apologised to his engineer for the outbursts.
"The poor guy has come on the radio and then I come back at him -– I will always say sorry," he said.
"Stuff does not come out like 'Hey buddy, just give me a little moment here'. It's like you are holding on to a bull and it's like 'Give me a frickin' second!'" Hamilton explained.
Schumacher tips Vettel to break F1 title record
Michael Schumacher has tipped his countryman and protege Sebastian Vettel to eventually beat his record tally of seven world championships.
In Austin at the weekend, Red Bull's dominant quadruple title winner surpassed Schumacher's decade-old record of seven wins in a single season.
German Vettel, still just 26, was visibly and audibly emotional when grappling with the significance of the feat, admitting Schumacher had been an "idol" in his youth.
"That's the first I hear of that," 44-year-old Schumacher, who retired for the second time at the end of last season, told RTL television when told his friend Vettel considers him a hero.
Schumacher said Vettel can now stand on his own two feet as a true F1 great.
"If you look at the consistency of his performances and how he achieves it, it is very unique," the great German said.
"There are some really good drivers in the field, but someone who is able to pull together all the facets of the sport so efficiently is very unusual," Schumacher added.
He admitted there are "many parallels" between Vettel's career and his own.
"I am sure that when he was a boy he would sit in front of the TV and try to analyse what I am doing. The nice thing is that even now he still calls me and asks questions," said Schumacher.
From that platform, Schumacher added, Vettel could go on to become F1's first ever eight-time world champion.
"I have always had the attitude that records are made to be broken," he said.
"It is clearly the case that Sebastian is able to achieve the seven titles, as he is still so young and hungry. Maybe he can even go past it.
"I will definitely cross my fingers for him."
Rosberg says Vettel's car performance 'crazy'
Nico Rosberg has described the performance of Sebastian Vettel's Red Bull as "crazy".
After a disappointing weekend of pace in Austin, the Mercedes driver admitted that watching onboard footage of F1's dominant champion did not cheer him up.
"I just sit and think 'Are you crazy? How does that work?'" Rosberg told the German newspaper Bild.
"What Sebastian's car can do in the corners is madness," he added.
On Sunday, Vettel surpassed Michael Schumacher's old record of seven wins on the trot in a single season.
The statistic was one of the only talking points of the US grand prix, with the possible exception of Red Bull's new all-time pitstop record of 1.923 seconds.
Part of the reason for the questionable spectacle in Austin was undoubtedly because of Vettel's imperious dominance.
"I have to admit," Mercedes' Toto Wolff told Austrian journalists, "when the audience can predict the winner with 90 per cent probability, this might be seen as boring."
But some blame should fall on Pirelli's shoulders, after the Italian marque - tired of the constant criticism of its heavily-degrading tyres - made an ultra-conservative hard compound choice for the weekend.
F1 has been warned by Pirelli that if the lack of cooperation remains the same up and down pitlane, fans will have to get used to the spectacle of one-stop races in 2014.
"It will be a topic of conversation in the coming weeks," Ferrari boss Stefano Domenicali is quoted by L'Equipe, "because we cannot always have races where the show is absent."
Alonso doubts Ferrari can be second best in 2013
Fernando Alonso does not think Ferrari can end its 2013 campaign by finishing runner-up to dominant champions Red Bull.
The Italian squad is currently sandwiched between Mercedes and Lotus in the lucrative constructors' world championship with just Sunday's Brazil finale to run.
But Spaniard Alonso said continuing to fend off Lotus is all Ferrari can now realistically hope for.
"There is nothing more we can do in this moment," he is quoted by France's L'Equipe.
"We are fighting to be in Q3 and scoring points on Sunday. Maybe it (finishing second) was just too high a goal.
"You have to be realistic and realise that second place was a dream," Alonso added.
However, while acknowledging that Ferrari's 2013 car is slower than the Mercedes and the Lotus, Alonso said he is proud of his personal performance this year.
Indeed, in Austin, he mathematically clinched the runner-up spot behind Sebastian Vettel in the drivers' chase.
"I am proud," he said, "because we clearly do not have the second fastest car. So finishing second is a great reward for me.
"But I would rather be tenth ten times and once champion, than to always finish second," Alonso insisted.
He is quoted by Spain's AS sports daily as admitting he is feeling "tired" heading into the last race of the season in Brazil.
"My preparation for this race (the US GP) was not ideal," said Alonso. "I was a week on the couch and in bed with headaches, dizziness.
"Physically I feel tired now and I felt stress throughout the weekend," he added.
"I think I'll be fine for Brazil, I am improving day by day and hopefully I feel a little better, less tired and I enjoy the weekend some more."