New Zealand driver Brendon Hartley appears to be taking heed of the message from his Formula One team about his future with them.
Following a strong ninth place finish at the US Grand Prix last week - Hartley on Saturday (NZ time) set the sixth fastest time in the second practice for Monday's race in Mexico.
However the 28-year-old from Palmerston North has picked up 24 points less than French team-mate Pierre Gasly this year and Toro Rosso team boss Franz Tost said Hartley must continue to impress over the final three events to retain his seat for 2019.
"He showed a good race in Austin. But nevertheless, if you look to the results, he has four points, Pierre has 28 points," Tost told reporters at on Saturday (NZ time).
"That means he has to improve his performance if he wants to stay in the team.
"First of all, we have to finish the season to get a clear picture and then I assume in December Red Bull will decide the driver line-up of Toro Rosso," he added when asked about a deadline.
Gasly is moving up to the main Red Bull team next year alongside Max Verstappen, with Russian Daniil Kvyat returning to Toro Rosso as his replacement.
Toro Rosso is the feeder team for Red Bull, giving debuts to rookies from within their young driver programme, but the conveyor belt of talent is facing a shortage of supply.
That could help Hartley's prospects, although Toro Rosso are interested in Thai-British driver Alexander Albon who is second in the Formula Two standings.
Albon recently agreed a deal to race in the all-electric Formula E series with Nissan, but did not take part in recent pre-season testing in Spain.
Tost confirmed the 22-year-old was in the frame but said negotiations with Nissan for the driver's release were confidential.
The speculation about his future appears to have fuelled Hartley and he said he has been buoyed by a "really positive" first day out in Mexico.
"To be in the top 10 in both sessions and to finish P6 this afternoon was great.
"I enjoy coming to this track, I've raced here a few times before and it's my second visit in a Formula 1 car.
"We did a lot of testing on the new aero kit. I really think it suits my driving style so today it felt like we started getting the car closer and closer to what I want.
"It's great to come out punching after a few really good races for me, and I'm feeling good about the weekend so far."
Hartley is in his first full season in Formula One, after making his debut in the latter part of the 2017 calendar.
The Mexican Grand Prix is followed by the race in Brazil, before the season concludes in Abu Dhabi on November 26.