The rumors in the Italian press hinted that arguments between team boss Steiner, and founder and owner Haas, including over the possible signing of Danica Patrick, could result in Steiner's departure.
And given that former Jaguar and Red Bull chief Steiner was at the centre of the team entry negotiations with Bernie Ecclestone and the FIA, his exit at this early stage might have serious implications for the entire 2016 project.
"I want to say that there is no break with Gene," Steiner, a German-speaking Italian, is quoted by Italy's Omnicorse. "The plans of the team are in continuous development according to the timeframes that we have.
"These things (rumors) can create problems for us in the negotiations that we are having," he warned.
Among the rumors was that talks with Ferrari about the supply of the power unit, transmission and other technology had stalled, but Steiner denied that.
"It (the negotiations) have never stopped. There has been no signing of contracts, but things are proceeding and they have their time," said Steiner.
The talks with Ferrari were said to be crucial, given the Italian marque's eagerness to have an American satellite team, potentially with Ferrari staff actually working in the Haas factories.
But Steiner insisted: "The Ferrari engineers are in Maranello, while we will build our team with our people.
"But it still is not the time to deal with these aspects, as we are working solidly on other priorities. We have achieved the entry for the F1 world championship and now we're going ahead," he said.
F1 business journalist Christian Sylt on Sunday wrote in the Telegraph newspaper that Team Haas will have about 200-250 staff.
Haas confirmed to the Daily Mail this week that a small management structure with a limited budget is the target.
"I don't see how you manage 500 people to run a race team. That just seems like too many," he said.
"So we're going to go with something where Guenther knows everything. He has to be able to talk to every person every day, so if you have 500 people you get nowhere."
|Steiner (Top) at odds with team owner Haas over Danica Patrick. There is no denying she looks good|
(GMM) An alternative to Danica Patrick is a 'pay driver', F1's newest team owner Gene Haas has admitted.
Earlier, American Haas said the world's most famous female driver, who already races for his Nascar team, "would be the dream driver" for his 2016 outfit.
However, 32-year-old Patrick said this week that she is "happy where I am".
At the same time, there are rumblings that Haas, 61, and his new team principal Gunther Steiner are having fundamental disagreements about the project.
Steiner, for instance, is said to be opposed to involving Patrick.
"This is just the latest divergence that every day becomes more pronounced," said Omnicorse correspondent Franco Nugnes, claiming the disagreements could lead to Steiner's departure from Haas.
In the end, the team may opt for the more traditional 'middle of the grid' F1 model, featuring an experienced name alongside a so-called 'pay driver'.
Haas told F1 business journalist Christian Sylt: "Having an American driver would be one of those 'knock it out the ballpark'-type moments.
"I think initially what we really would like is probably a veteran formula one driver, preferably someone who has driven the 2014 car, to help us.
"Then the remaining seat would go to someone who has a lot of promise, that could be an American, or someone else that brings some sponsorship money to the table too," he added.