Leclerc was the veteran Kimi Raikkonen's replacement, switching from Sauber after just one year in Formula 1. Windsor believes Leclerc, and his ambitious personality and aggressive driving style has thrown Sebastian Vettel off his game.
Ferrari are yet to win a race in 2019, despite recording three pole positions, in Bahrain, Canada and Austria. Leclerc has achieved two of those pole positions, but Windsor believes the Monegasque's arrival at the Italian team has had more of a detrimental impact on its performances.
"It is fascinating to see what effect he (Leclerc) has had on Sebastian Vettel and Ferrari," the F1 journalist explained in his YouTube vlog. "I think this explains why Ferrari has not yet won this year and is not competing for the title as initially thought.
"That is because of the pace of Charles Leclerc and the way in which the team has been brought out of balance. Sebastian's self-image is therefore also out of balance, as is the way in which he does his work as a driver and as a key figure at Ferrari.
"This has put the whole team in a state of confusion. They now know more or less which direction they want to go, but nothing is really determined in details. Charles is there and he is confusing Sebastian. As long as this is the case, it is difficult for Ferrari to find the focus and direction they need. Not only about how they adjust the car but also how they use it."