Giovinazzi has failed to pick up points so far in 2019, while teammate Kimi Raikkonen has scored all of Alfa Romeo's, which currently places it fifth in the constructors' championship.
Last time out in China, Giovianzzi's weekend was hampered by a recurring power unit issue, which saw him sit out FP1 and qualifying. Vasseur says that Giovinazzi has shown glimpses of speed, but is failing to put the whole package all together.
“It’s frustrating for everybody because I think from the beginning Antonio showed that the pace is there,” Vasseur said. “He was very fast in Melbourne Q1, did a better lap time than Kimi managed overall, or it was more or less the same.
“In the race in Bahrain, the pace was there, in quali he did a small mistake at the end of the lap but he was a bit faster than Kimi also. He’s struggling to put everything together and the team didn’t help him [in China].
“It’s a shame but I think he will recover and if you have a look on last year the start of the season was also difficult for our drivers.
"We are very pushy with them, very supportive and they were able to improve during the season and we have to do the same with Antonio. I think he has also the advantage to have Kimi as a leader and Kimi is able to show not only the pace but also the way you have to manage the weekend.
"For Antonio it will be helpful. At least the pace is there, it’s important for us and important for Antonio and his mind but I am convinced he will do it.”
Charles Leclerc, who made his debut with the same team last year when it was called Sauber, starred during his debut year.
When asked if he sees comparisons between the two Ferrari juniors, Vasseur said: “It’s too early and you know that the next step is always the most difficult.
“It is the same for Charles, to move from the back to the best of the rest was one thing and now to move from the best of the rest to win races it’s another story.
“For Antonio he is able to do well and I hope that he will be able to put everything together quite soon and I am hopeful. It is not the first time in my life that I find myself in this situation.
“I’m not at all worried about the situation. I don’t want to make any comparisons with Charles but just to remind you that Charles was presented like the world champion in Barcelona.
“Then I had the question in the press conference in Bahrain or something like this, after the race that somebody asked me that 2018 was probably too early for Charles.
“Then after 10 races it was ‘Okay, he needs to go to Ferrari and he will be the next world champion’. It’s not that one day one guy is doing a good job and he will be world champion and because he’s making a mistake he will never achieve it.
“I have full confidence, more than this, in Antonio. He showed that he was able to do the job under pressure in F2, he was able to do the job under pressure in Melbourne in Q1.
“He has very good feedback and he is working very well in the team even in the tough times. For example [qualifying] it was 200% the fault of us and nothing to do with Antonio. That’s life.”