Sirotkin is set to move from Formula Renault 3.5 to a grand prix drive with Sauber next year, as part of Russian investment into the Swiss team.
The 18-year-old is already working through an aggressive programme to get him ready for that step up, which is set to include several days of running in recent F1 machinery.
"I am learning a lot," Sirotkin told AUTOSPORT. "Since this whole Formula 1 story started I feel much stronger now.
"I don't know if people can see it from the outside but I am much stronger and I think some of my performances have shown this.
"I feel more experienced, and I already have more understanding of how it works at the top level."
How Sauber was saved: the inside story
Sirotkin, who has had only one of his planned days in an F1 car so far, believes it will only become clear if his development programme has worked when the 2014 season starts.
"Everything is going as it should be, step by step," he added. "We have only just started.
"But we are doing what we can to be prepared. Next year we will see what we did right and what we did not.
"We just have to wait a bit. I have had just one proper test day, and I didn't spend much time driving the car.
"It was more about working with the engineers and all of the things you have to learn. So far it is positive."
Sirotkin finished ninth in his rookie FR3.5 season this year, taking two podium finishes.
- Sports & Recreation
- Motor Racing