The dynamic in the Italian outfit changes this year as team veteran Pierre Gasly has moved on and been replaced by rookie Nyck de Vries.
While the Dutchman is in his first year, he is older than Tsunoda and brings experience from other categories, as well as the knowledge gained with other F1 teams.
Tost has made it clear that he expects the newcomer to make an impact from the off.
Longer term Tsunoda faces potential competition from other drivers making their way through the Red Bull ranks, and thus Tost wants him to raise his game this season.
"He should not crash. He should use his good driving style and his aggressive driving style and his talent because Yuki is, believe me, a very high-skilled driver," said Tost when asked about Tsunoda's approach for this season.
"He just has to get it together, everything. And he is now in his third season. I expect that he learned a lot in the last two years, and he is very young, we must not forget.
"He's worked really hard during the winter months especially on the physical side with his new coach, and I expect from both drivers a good performance. And also from Yuki, not crashing!"
Tost conceded that Tsunoda has had to work on his emotions while at the wheel, his often colourful radio messages having become his trademark.
"Yuki came into F1, he was very young," said Tost. "And if something didn't work as he expected, then he showed his emotions. I said to him, it's not so good. Not because of coming up with emotions, but it takes away concentration and energy from you during driving.
"He should be more concentrated on driving the car, instead of shouting around on the radio, because anyway, it doesn't help anyone.
"You can say afterwards if something went wrong. But once in the car, it happened, it's gone, it's past tense, therefore be concentrated on what's going on, that's much more important.
"And I hope that he will realise this. Because once more, it takes away concentration, it takes away to get forward."
Asked if it was a make-or-break year for the Japanese driver he said: "I wouldn't say make-or-break year, but he has to show performance, of course. And if he races using all the abilities he has, he will bring home good results. I'm convinced about this."
Tost said the question of who might lead the team in terms of pushing car development remains open.
"We don't have a number one or number two driver," he insisted. "Both drivers are being treated equal. A leading driver from the technical side, we will see. Because Yuki has more F1 experience.
"Nyck has generally more racing experience. I think they will or I hope at least that they will work very close together, and that we can get out from both of them the best sides."
