Sergio Perez admits he feels less "comfortable" in his Red Bull car after recent upgrades.

Just over a month ago, the Mexican appeared to be gaining momentum over teammate Max Verstappen after victory in Monaco and pole in Baku.

However, since then, the reigning world champion has asserted himself as the clear lead driver again at Red Bull, with Perez struggling to match the Dutchman's pace in recent races.

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While a poor weekend in Canada ending in retirement didn't help, The Race believes recent upgrades to the RB18 have shifted the handling balance more towards the front, a characteristic that favours Verstappen more than Perez.

And Checo confirmed his confidence in the Red Bull car has ebbed as more development is done.

“Well, it’s just going away from me in terms of how comfortable I was in the beginning,” he said.

“But saying that, I’ve had only two races [of this] and last weekend I wasn’t up to it, I was feeling pretty bad, so I think this [Austria] is the first weekend where I will see really.

“I think I’ve got some work to do to understand what’s going on and hopefully have a more straightforward weekend here.”

In the championship, Perez did close the gap to 34 points at Silverstone, as he recovered from an early front wing change to P2 while Verstappen dropped to P7 with a damaged floor.

But he knows he can't afford any more slips if he wants any chance of fighting for the title.

“Having another couple of zeros will kill the championship for sure,” Perez said.

“But hopefully reliability issues are gone now and we’re able to finish races, that’s the most important [thing].”

Another question though is whether Red Bull really considers the Mexican as a championship contender.

And motorsport advisor Helmut Marko only furthered the narrative that Sergio is really a 'No.2' ahead of the team's home race.

“Max can drive any car fast, that’s why having Sergio Perez as his teammate is perfect," he told the Red Bull website.

“Checo doesn’t try to fight but does everything he can, and that can lead to victory as it did in Baku last season.

“The two work very well together and Checo is having a great season but still, when it comes to sheer speed, Max is usually the faster of the two.”