Alpine CEO Laurent Rossi believes F1 is treading a fine line with its scheduling and has insisted 23 races is a "big maximum".
F1's record-breaking calendar takes place in a condensed season this year between March and November, pushing teams to their limits across the globe.
The current Concorde Agreement stipulates a maximum number of 25 races a year as the sport looks to expand and take advantage of an increase in exposure and interest in recent seasons.
Whilst the sheer number of races is enough to draw concerns, the continued use of triple-headers has also raised eyebrows up and down the paddock, although F1 sporting director Steve Nielsen has suggested teams are now more prepared for the scheduling.
Asked if the 22 races of 2021 were too high an amount, Rossi told an end-of-season media call including GPFans: “It's a lot. It's a lot for the teams, for the mechanics. They're having a crazy lifestyle.
“At the same time, it's great for the show, it's great for the drivers, they love it. If you give them 40 races, they will probably race 40 times during the year.
“Anyways, when they're not here, they race their karts and all this stuff.
“But there's a fine line in terms of sustainability for the people. I think 23 is the maximum, a big maximum.
“I will personally probably imagine that the less double-headers, triple-headers you have, the better. It's slightly on the higher side of the spectrum I think.”