Helmut Marko, a close advisor to Red Bull's billionaire owner Dietrich Mateschitz, contrasted triple world champion Vettel's attitude to Alonso's in an interview with the company's in-house Red Bulletin magazine.
The Austrian said the 25-year-old German, who beat Alonso to the title last year, was a phenomenon who "shuts himself off from the rest of the world, so that he can still call on reserves that other drivers might not have".
Alonso, by contrast, was "busy with politics and funny comments".
"I believe we saw the stress he (Alonso) was under towards the end of the season. Saying things like, 'I'm competing against (Lewis) Hamilton, not Vettel,' and 'I'm up against (Red Bull designer Adrian) Newey'," added Marko. "These psychological skirmishes - we said: 'Just ignore him."
Alonso had a 42-point advantage over Vettel at the mid-season break last year but ended up losing out to the Red Bull driver by three points.
As the battle heated up, so too did the psychological warfare and even as he celebrated the title Vettel spoke out about what he saw as 'dirty tricks' and attempts to unsettle him and the team.
Alonso, who was voted driver of the season by team principals for the way he took the fight to Red Bull in a less competitive Ferrari, made light of Marko's comments and turned them back on his rivals instead.
"I enjoy reading that Red Bull still think we will be the strongest rival for next year! And this even before start testing!! Flattered..;)," declared the Spaniard on his Twitter feed.
The first pre-season test of 2013 starts in Spain on Febuary 5 with the opening race in Australia on March 17.
In other comments, Marko portrayed Vettel's Australian team mate Mark Webber as a driver who could win races but struggled to handle the pressure when in with a real chance of the championship.
"It seems to me that Webber has on average two races per year where he is unbeatable, but he can't maintain this form throughout the year," he said.
"As soon as his prospects start to look good in the world championship, he has a little trouble with the pressure that this creates. In comparison with Seb's rising form, it seems to me that Mark's form somehow flattens out.
"Then, if some technical mishap occurs...he falls relatively easily into a downward spiral."
Webber had the greater chance of taking the title in 2010 when he and Alonso were the top two going into the final race, but Vettel seized the crown instead for the first of three championships in a row.
That, Marko suggested, had been a psychological blow by the younger man that had gnawed at Webber's confidence