Formula 1 and the sport's governing body, the International Automobile Federation (FIA), have both said the calendar remains as scheduled despite conflict in the Gulf region and the Iran war.
FIA president Mohammed Ben Sulayem told reporters this week that the situation was currently "fine", the races were going to happen and he would be happy for his staff and teams to go. Qatar is scheduled for November 29 and Abu Dhabi for December 6.
Sainz, a director of the Grand Prix Drivers Association (GPDA), sounded less sure.
"I think they seem very convinced that it's going to go ahead. On my personal side, I'm not speaking as the GPDA, it's very difficult to be convinced right now," the Spaniard told reporters on Thursday ahead of the US Grand Prix in Austin.
"There's still plenty of things happening in the Middle East and also there is obviously an election that is going to happen in the US and things that are going to happen in the political side of the world that could affect the next month, month and a half.
"So I think it's relatively premature to be so convinced. But as it stands, we would go to Qatar and Abu Dhabi and if the FIA and Formula 1 decide that's still safe and a good scenario I think we as drivers have to go with whatever they say."
The US midterm elections are on November 3. President Donald Trump said on October 8 that the US will not launch an attack on Iran before those elections.
The US and Israel launched strikes on Iran in February, with Tehran firing missiles and drones at Gulf neighbours that host American forces.
Sainz said the drivers lacked inside information and needed to trust in the decision-making of those running the show.
"The world can change a lot in the next month and we need to stay diligent and reactive to whatever happens and not just go because we want to go right now," added the Spaniard.
Italy's Imola circuit has been lined up as a possible Plan B, although winter cold in early December could also make that challenging.
McLaren's Oscar Piastri said he would be happier going to Australia at that time of year.
"We might have to get some snowploughs out if we race in Imola," he added. "I think Imola is being kind of touted as the replacement. Hopefully it's above zero."