The Haas Formula 1 team are still in talks with 10 drivers for their two race seats for 2016, but they hope to finalise their line-up by September.
The American-based outfit will be the only new entrant on the F1 grid next year and they will be powered by Ferrari.
Founder Gene Haas has previously admitted that current Force India driver Nico Hulkenberg, American Alexander Rossi as well as Ferrari test and reserve duo Jean-Eric Vergne and Esteban Gutierrez are on the list.
However, team principal Guenther Steiner says they are still holding discussions with several drivers, but he has made it clear that they want some experience in their line-up.
"We are talking with about 10 people – some are higher up the list, some are lower, but we also want to see who is out there," he said. "It's still difficult to find out who is actually available, because it hasn't been decided who is going where.
"We would like to make a decision by the end of summer because then we can get prepared for the driver. The car needs to fit the driver.
"Also we've got time to explain to our driver what we are doing because we are new and he needs to help us as well; what do you want from us to help us get ready to do things?
"So by September I hope we have made a decision for at least one, if not two. Ideally it would be two.
"But we have interesting candidates, which is very nice for us, drivers with a good reputation who are talking to us seriously, so I hope we can pull some of them off."