David Coulthard believes that Sergio Perez needs a "major rewrite" in order to more closely match teammate Max Verstappen in 2023, and has also warned the Mexican to be aware of reserve driver Daniel Ricciardo.
Perez will enter into his third season at Red Bull in 2023 after finishing the 2022 campaign in third place, some 149 points away from championship winner Verstappen.
While the relationship between the two drivers has mostly been amicable during their time together, there were signs of tension in the latter stages of 2022 when Verstappen refused a team order to let Perez pass him on the final lap of the Brazilian Grand Prix, the penultimate race of the year.
Team boss Christian Horner has stated that he does not expect any further issues between the two, but Coulthard thinks that – in terms of on-track performance – Perez must up his game if he wants to contend against Verstappen.
Coulthard: Knowledge is there for Perez to lift performance
"For Checo to look at how many victories Max had and how many he had, it's not like he is just having to polish a few corners. This is a major rewrite, a software update," Coulthard told the BBC.
"If you use the same ingredients in the cake you will get the the same cake. You need to change it if you want something different.
"He has access to the data of the World Champion. He can see where he's quicker, where he's slower. Checo will be quicker in some areas. It's just Max is putting it all together more often than not.
"All the knowledge is there for Checo to lift his performance. If he does then the World Championship is there for him to put his hand on.
"If he doesn't, then he will be another driver, like myself, that won a few Grands Prix."
Coulthard believes that Perez's F1 destiny is "in his own hands", and that Verstappen is the "benchmark" for his performance.
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Perez must 'defend territory' against Ricciardo, says Coulthard
Ricciardo will return to Red Bull as a reserve driver in 2023, having voiced his hopes of making a comeback to the F1 grid in 2024.
As such, Coulthard thinks that Perez faces an additional challenge in keeping any threat posed by Ricciardo at bay.
"Checo will see that there is a real substitute driver there," Coulthard explained.
"Having been in a similar situation to Sergio where I was up against Mika [Hakkinen] and Kimi [Raikkonen, at McLaren], you just have to leave no stone unturned.
"You do physical training but the only way he can improve his qualifying speed is in the car or in the simulator.
"In nine years at McLaren, I did every test and never missed a race, even when I felt terrible, even when I felt like I was going to be sick after testing, because I knew the minute I let the test driver get in the car it became an opportunity to show how good he was.
"If I don't let him get in the car he can talk all day long. You have to defend your territory."