"It's not easy for anyone, especially mechanics and engineers and people who from now on have to fight for their future. None of us know what will happen," he said in the Interlagos paddock on Thursday.
"We just have to assume that the team will continue and that we still have to do the best possible job. People are being very professional and keeping their heads down. I feel very comfortable with them."
The Madrid-based team, who have yet to score a point in three seasons, have struggled for cash since their debut and their situation has become more precarious as Spain struggles with a debt crisis.
The majority of Formula One teams are based in Britain, within easy reach of the Silverstone circuit and essential suppliers as well as a steady supply of engineering expertise, with HRT the only Spanish-owned outfit.
Their owners Thesan Capital said this month that the team, who also have Indian Narain Karthikeyan as one of their drivers, was up for sale and talks were ongoing with a number of interested parties.
However many in the paddock are sceptical about any buyer emerging at a time when all teams are scouring the world for investment. Should HRT fold, the sport will be left with just 11 teams.
"The backing from Spain has been smaller than expected mainly because we have inherited a very difficult economic situation at home," said De la Rosa.
"We cannot ask really for more support for the team when people are losing jobs etc."
Asked about reports of redundancy notices being issued in Spain, the driver said nobody with the team in Brazil had experienced that.
"All I know is that we are here and that everyone here has not received anything...What happens after is unknown," he said.
"We don't know much about what will happen, I don't think anyone knows at the moment. I hope the team continues but at this moment in time I cannot say any more."
Formula One has seen a long list of teams come and go over the years, including illustrious ones such as the original Lotus operation.
De La Rosa, who started his Formula One career with now-defunct Arrows in 1999, said only Ferrari, McLaren, Red Bull and Mercedes could consider their futures to be in any way guaranteed.
"You only need one investor or one big sponsor to pull the plug and it really starts shaking," he said. "I think other teams could be in the same situation or worse than us."
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