Helmut Marko has lifted the lid on the “toxic” relationship between Max Verstappen and Carlos Sainz when they were last Formula 1 team-mates.

They raced together for Toro Rosso for a little over a year, before Verstappen got the call-up to join the main Red Bull team. Sainz remained with the sister squad until the end of 2017, when he left for Renault.

In their one and only full season together, despite being the younger racer, Verstappen comfortably got the better of his team-mate. He scored 49 points compared to Sainz’s total of 18, which paved the way for the Dutchman to leapfrog his fellow Red Bull junior in the race for a seat with the top team.

Given they were competing against each other for that change, it is only natural that there would have been an internal rivalry there. But, speaking to the Red Bulletin, team adviser Marko paints the picture of a total breakdown of their relationship.

“For a long time, he lived in the shadow of his father, the two-time World Rally Champion,” the Austrian said of Sainz. “He was unfairly saddled with the image of being the spoiled son of a racing driver whereas on the contrary, Carlos had to fight consistently to get ahead.

“It was his bad luck to get Max as a team-mate. The atmosphere between the two at Toro Rosso was quite toxic. In the set-up we had at the time, I couldn’t see a way of keeping him with us and so he moved to Renault, McLaren and then on to Ferrari.”

As Marko said, Sainz went on to make it to one of F1’s top teams despite his Red Bull progression being stunted by Verstappen. Indeed, the Spaniard was one of only three drivers t

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His current Ferrari deal expires in 2024, and it is understood Sainz will be offered fresh terms. But the length of contract on offer is believed to be shorter than the one sanctioned for team-mate Charles Leclerc, with the Italians keen to keep one of their seats relatively open – which could potentially spark the Spaniard’s exit in the next couple of years.

According to Gazzetta dello Sport, it could even trigger Sainz’s return to the Red Bull family. The publication claims the 29-year-old is on the shortlist of potential replacements for Sergio Perez, who is in the final year of his current deal and fighting for his future with the team.

Sainz would no doubt be one of the stronger external candidates. But Red Bull do already have good options in house, most notably Daniel Ricciardo who has made no secret of his desire to return to the seat he vacated more than five years ago