Renault insists Robert Kubica will not race in Formula 1 this season and that his Hungaroring test is purely to evaluate his chance of a 2018 comeback.
News Kubica will drive the current Renault next Wednesday fuelled speculation he could replace Jolyon Palmer as early as August's Belgian Grand Prix - a suggestion Renault managing director Cyril Abiteboul dismissed.
"We continue to support Jo and there is absolutely no change of plan," Abiteboul told Autosport.
"It is true that with Robert we feel we need to investigate a little bit further after all the tests we have done.
"Obviously there have been the tests we did with the 2012 car, but also we have done other things - medical checks and simulator work that I don't really want to elaborate on.
"We want to have a closer look about how realistic it would be for Robert to drive again in a modern F1 car, and possibly into a racing context.
"The last opportunity to at least do the test in a modern F1 car was the Hungary test, and we are taking that opportunity.
"But that is really something that is more medium to long term.
"It is not a short-term plan and it is not a short-term option to do anything with our driver line-up."
Abiteboul insisted a strong test performance from Kubica would not guarantee a 2018 seat.
"Robert could be a candidate for 2018 but before we can really consider him as a candidate, we need to see how he will cope with cars with more downforce and with more power, because clearly the  car he has been driving up until now is not representative," he said.
"Frankly, even if he does well, it does not mean immediately that we will decide to go for him for 2018 because there is more we need to look into."
He added that he had reassured Palmer over the implications of Kubica's test.
"I told him that Robert is not an immediate threat," said Abiteboul.
"Clearly we are looking at options for 2018, and Jo could be an option for 2018. That is in his hands.
"What we are doing with Robert has nothing to do with what Jo does this weekend or even after the summer break.
"But there will not be any replacement driver in Spa, as I've seen stories suggesting that too.
"I can confirm that Jo will be driving in Spa and the plan is for him to drive until the end of the season."
This weekend in Hungary, Palmer will get the new floor team-mate Nico Hulkenberg used at the British GP.
Abiteboul believes Palmer needs to rebuild his confidence, but must "perform like any driver who makes it to F1 has to perform".
"I am not going to take away the fact that there is pressure," he said.
"It is a competitive environment and that is never going to go away. But it is not a short term pressure."