Contrast the way that Williams F1 team boss Claire Williams defended her new driver Sergey Sirotkin against 'pay driver' jibes this week, with the serenity of Charles Leclerc's first public appearance as an Alfa Romeo Sauber F1 driver.

Williams launched its new line-up and projected images of its new car on the walls of a smart event in London's Shoreditch on Thursday. While much attention was on the aerodynamic makeover – which is going to be make or break for Williams in 2018 – other sections of the media were all about the 'pay driver' label on the Russian debutant.

Sergey Sirotkin, Williams Photo by: Glenn Dunbar / LAT Images

Sirotkin is reputed to bring $15m a season for two years to Williams from wealthy Russian backers.

Williams was tough: "It's nothing new in F1 that drivers come with money, and thank goodness that they do," she said. "It would be incredibly naive… saying 'He's just a pay driver.' It's great if a driver has financial interests from partners - it's great for the team, it's great for the driver.

"This is an expensive sport, not just F1 but at grassroots level as well. We'd miss out on so much talent coming into F1 if drivers didn't have financial backing supporting them through the junior formulae and bringing them into F1."

I always prefer to let the driver do his talking on the track, and if Sirotkin is quick and consistent, gets results and looks every inch a grand prix driver, then he will be welcome in the sport.

Sergey Sirotkin, Williams FW40 Photo by: Zak Mauger / LAT Images

The benchmark that is always trotted out when talking about 'pay drivers' is Fernando Alonso, who had backing from the Santander bank, as well as Spanish insurance and ceramics companies when he was at McLaren and Ferrari. His 2001 Minardi on debut was sponsored by Spanish telco, Telefonica.

But he got ahead in F1 as part of Renault's development programme – having turned down a deal with Jean Todt to test for Ferrari and then become a race driver. Instead he went with Flavio Briatore and was world champion a few years later.

The acid test of a pay driver is very simple; would Driver X be at the team if he didn't have the money behind him? How about Sergio Perez? Of course he would. So he’s not a pay driver, he’s a very good driver who attracts backers.

Charles Leclerc, Marcus Ericsson Photo by: Alfa Romeo

A more serene arrival

Meanwhile in Italy this week, Alfa Romeo laid on an event where Leclerc and his teammate Marcus Ericsson were 'introduced' to Alfa Romeo history with the media. It was elegant, serene and stylish. They discussed Alfa legends Farina and Fangio, drove the Stevio and Giulia models and talked about the season ahead.

Leclerc is a Ferrari development driver and the reigning F2 champion. He won the championship in his debut season and in a dominant manner. Prior to that he was GP3 champion.

Is Leclerc a pay driver? Of course not.

Then again, his arrival at Sauber has brought with it some very tangible benefits for the team; from Alfa Romeo title sponsorship, to new Ferrari V6 engines and "strategic, commercial and technological cooperation".

Charles Leclerc, Alfa Romeo F1 team introductions Photo by: Alfa Romeo

Sauber should first of all survive and then move up the grid significantly as a result of the support, which is motivated by Ferrari chairman Sergio Marchionne. He wanted to bring the Alfa brand back to F1 after 30 years. It means stability and growth for the team.

One could argue that the support is the other way around and that Marchionne was going to do the Sauber deal anyway, for marketing and political reasons; and Leclerc just benefitted from being in the right place at the right time.

But the timing and the opportunity for Ferrari to school one of their most promising talents were ideal for this to all come together and Leclerc comes to the team with a lot of oomph behind him. Another Ferrari protege, Antonio Giovinazzi, is also waiting in the wings should Ericsson fall from grace.

"Being part of the return of a great brand like this is a great honour," said Leclerc. "Everyone is saying to me 'you're racing for Alfa Romeo in F1', almost forgetting about Sauber!

"What has struck me is the passion of the people who work there [at Alfa Romeo]. Their eyes light up when they are looking at the cars, I've not seen that kind of enthusiasm too many other times.

"Having Ferrari's support behind us will certainly be a great help. Our car is beautiful and I can't wait to launch it and drive it finally on the track."

Charles Leclerc, Ferrari SF70H Photo by: Joe Portlock / LAT Images

Leclerc’s long-term ambitions

The word from colleagues in Italy is that Ferrari's plan for 2019 is to promote Leclerc into Kimi Raikkonen's seat at Ferrari – provided that he develops and performs in line with their (high) expectations.

The caveat to that is the possibility that results either way make Daniel Ricciardo a more suitable replacement and Leclerc is given more time to develop.

Knowing that there is a chance of a Ferrari seat in your second season is a huge pressure to put on a 20-year-old. It could be like becoming a rock star overnight, and then be expected to release number-one records regularly.

That is what happened when Alonso got the Renault seat for 2003 and got his first pole and win soon after - or Vettel when he moved up to Red Bull in his second season. Alternatively, Leclerc could spend a few years closer to the back of the grid learning his craft, like many others.

"This year I just want to concentrate on gaining experience and growing as quickly as possible so I can get results,” said Leclerc.

“The F2 title gave me confidence. But the jump up to F1 is enormous."