Ferrari star Sebastian Vettel said he is confident his team will sign up the right development talent.
"I'm not a big fan of the simulator, but it is a very important tool for improving the car," Vettel told Corriere dello Sport.
"We must thank the guys who work there, because it is not the best thing to do on a Friday evening.
"For next year (2019) we do not know who will be there, but I think we will be able to find drivers who can do the job well."
Vettel finished second to Lewis Hamilton in last year's F1 championship, while Ferrari also finished in second place in the F1 constructors' championship.
Working with such a prestigious team would be tempting for Hartley, who has also been linked to racing for Porsche in Formula E next year.