Daniel Ricciardo is poised to make his formula one race debut at Silverstone next weekend.
Australian media reports say the 21-year-old, backed strongly by Red Bull and until now the Friday driver at Toro Rosso, will replace HRT regular Narain Karthikeyan at Silverstone.
The Spanish team has been contacted for comment.
Ricciardo, who turns 22 on Friday, had been widely tipped to debut at junior team Toro Rosso this season but both Jaime Alguersuari and Sebastien Buemi have performed strongly enough to keep their race seats so far.
Just days ago, Red Bull driver manager Helmut Marko hinted that Ricciardo is close to joining the grid.
"In the simulator and in practice, his results are very good, but we need to see what he can do in the race," said the Austrian.