Daniel Ricciardo’s door back to F1 this season has been firmly shut, with AlphaTauri boss Helmut Marko saying the Australian was not a possible replacement if the team axes struggling Nyck De Vries.

De Vries is one of just two drivers this season yet to score points, with two 14th place finishes followed by two crashes and an 18th.

There has been talk in recent weeks that the Dutchman could be sacked in a stunning mid-season switch, with Ricciardo’s name floated as a possible candidate to take over at the struggling secondary Red Bull team.

Ricciardo is currently a Red Bull reserve driver, and has had a seat fitting both for that team and for their sister team Scuderia AlphaTauri. He previously raced for AlphaTauri in its previous guise Toro Rosso, before being promoted to Red Bull’s senior team in 2014.

But Red Bull’s motorsport adviser – and the traditional head of their junior driver program – Dr Helmut Marko said the team isn’t ready to pull the pin on De Vries yet.

“We have spoken to De Vries and he is of the same opinion as we are: He has to improve,” Red Bull motorsport advisor, Dr Helmut Marko, told F1-Insider.com.

“The gap to teammate Yuki Tsunoda, who is doing a great job, is too big.

“To use footballer’s language: Nick got the yellow card, but not the red one yet. If he improves, a change of driver will not be an issue.”

If De Vries’ struggles become untenable, Marko said AlphaTauri would turn to a young driver instead of 33-year-old Ricciardo.

“If the worst came to the worst, we would fall back on our pool of young talent,” he said.

“We are talking specifically about Liam Lawson and Ayumu Iwasa. Ricciardo is not an issue.”

Another name that had been thrown up - Mercedes reserve driver Mick Schumacher - is also not in the picture.

“He’s a Mercedes driver and he’s not in our plans,” Marko said. “Accordingly, [team principal] Toto Wolff is responsible for him.”

Lawson is a reserve driver with Red Bull, and drove for both the senior outfit and AlphaTauri in practice sessions last year. He is likely to get more minutes in Friday practice sessions this season.

The New Zealand youngster was viewed as a strong contender to De Vries for the AlphaTauri seat before this season, after Pierre Gasly’s departure to Alpine, but lost out to the Dutchman after De Vries scored points in a one-off showing for Williams at least year’s Italian Grand Prix.

Lawson finished third in last year’s F2 Championship, and is currently impressing in Super Formula in Japan – winning his debut race.

The other youngster named by Marko is Iwasa, who could join Tsunoda to deliver AlphaTauri an all-Japanese driver line-up. The 21-year-old gun has impressive race pace – particularly valuable given the team’s desperation for points.

Iwasa is a current F2 title contender after two wins in the first four rounds of the season.