Toto Wolff says Formula 1 needs to have a "think about it" as a sparse crowd turned up for Friday's practice for the German GP.
Formula 1 was in for a shock at Hockenheim on Friday where the grandstands were largely empty while there are still plenty of tickets available for Sunday's race.
It is yet another sign that Formula 1 fans are turning off with reports revealing that television figures are also dropping.
Wolff says something needs to be done.
"It's not satisfying," the Mercedes motorsport boss told Autosport. "If you compare Hockenheim Friday to Friday at Silverstone and Friday in Austria, it's a different world.
"We have to understand why that is. I'm not sure whether we have an exact number for Sunday already - you know, there are lots of people probably deciding at short notice, depending on the weekend - and we have to analyse the phenomenon.
"If the weekend continues like it does now, we need to think about it."