Toro Rosso has run through four different drivers in the past two Grand Prix, leaving returnee Daniil Kvyat and stand-in Brendon Hartley both unsure of their futures following the United States Grand Prix.

The switches began when Pierre Gasly replaced Kvyat in Malaysia after a run of poor performances, before Carlos Sainz Jr. was released to join Renault, bringing Kvyat back at the same time as Gasly was sent to Suzuka for the Super Formula finale which caused Hartley's call up, despite being dropped as a Red Bull junior in 2011.

Both drivers put in strong performances this weekend, with Kvyat achieving his second points finish of the year in P10 and Hartley making an extremely strong debut, in his first race in single seaters for six years, moving from the back of the grid to finish P14 which left both drivers thrilled with their performances.

"It was a great race. It was more than perfect, I must say,” Kvyat said. “My best race of the season for sure. Fantastic. Got the maximum out of our car, very happy about the result.”

Hartley described his F1 debut as "tough, awesome though" and when asked if he'd do more Grand Prix he said: "I would like to but I guess I have to see now. I don't really know.

"I think it's clear I would love to be here. Up to now I haven't been asking the questions, I haven't been pushing anyone on that."

Kvyat has been assertive all weekend that he deserves answers to his future with Red Bull but seemed equally uncertain about even the next race, despite a 'perfect' weekend.

Asked about whether he would stay he said: "I don't know. I've done a perfect Friday, a perfect Saturday and an even more perfect Sunday, so I don't know what else I can do."

With Gasly set to return from the cancelled Super Formula finale, only one of Kvyat or Hartley could take a seat at Toro Rosso for the rest of the season - or even next year. With the decision in the hands of Red Bull programme manager Dr. Helmut Marko, diplomacy will be key to their chances - and tolerating uncertainty until then.

Hartley said he was just trying to play his cards right and is eager to get a decision ahead of next weekend’s Mexican Grand Prix.

"Even when I first had the call to come and have a test on the simulator, I didn't ask anything, I just did the job. I've tried to do the same this weekend. Let's see. I know there's another race coming up pretty quick, but I'm not holding my breath."