Having drafted Andre Lotterer in for this weekend, the British-based squad's future driver lineup is unclear. Regular racer Kamui Kobayashi could return - and should at least be in the car for his home grand prix at Suzuka - but beyond this his future is not certain.
According to reports today, the team are now considering the young Spaniards, who are currently one-two in the FR3.5 standings and have taken five of the series' past six race wins between them. Both are highly rated and could also offer financial support to the struggling outfit.
Sainz is backed by Red Bull and was the strong favourite to replace Jean-Eric Vergne at Toro Rosso next season until Max Verstappen landed the role. He has also been linked with a spot at Caterham for some time, though this was assumed to be as preparation for a Toro Rosso berth in 2015.
His countryman Mehri is a former F3 Euro Series champion and spent two seasons racing for Mercedes in the DTM, scoring a podium at Hockenheim last season. In their FR3.5 title battle, Sainz currently leads Mehri by 39 points with three double-header weekends remaining.
Despite being comprehensively out-qualified by newcomer Lotterer today, Marcus Ericsson's place at the team is believed to be secure thanks to his financial input.