Gunther Steiner has expressed concerns amid rumours about the next tweaks to the 2021 Formula 1 race calendar.
Turkish media, including the sports broadcaster S Sport, claim that the decision to axe Canadian GP substitute Istanbul Park from the calendar has now been taken.
It was rumoured Turkey's loss could be compensated by adding a second race to another existing circuit - like the Red Bull Ring or Paul Ricard.
But a second Austrian GP would mean teams face an unprecedented four consecutive race weekends on the trot.
"Basically, almost anything is possible," Haas team boss Steiner said.
"But there are limits to what can be expected of our people. If we were to tell our staff not to come home for up to six weeks, it would be unfair. We have to be careful not to overdo it in terms of the burden on the people.
"So I don't see that as a good solution."
Steiner said the existing 23-race schedule would have been arduous enough in its original form.
"We all had a difficult season in 2020 and if all of the races take place this year, the end of this year will also be difficult.
"I hope they are not cancelled, but I'm not sure if we can race with this schedule for a couple more years," he added.
It is believed Formula 1 may simply scratch the June 13 race date from the 2021 calendar rather than try to replace Turkey with Mugello or the Nurburgring, as is rumoured.
