Currently there are 11 different teams consisting of two drivers each on the grid, but that could change for the 2015 calendar.
The future of backmarkers such as Caterham and Marussia are likely to under threat if such a change did happen, while Lotus and Sauber are both reported to be experiencing financial difficulties.
F1 chief executive Ecclestone has in the past signalled a preference for bigger teams such as Ferrari to run a third car - and he has now suggested that a decision could be made in the near future.
"We'll know after the next two or three races. It's always been on the cards that if we lose up to three teams then the other teams will run three cars," Ecclestone said ahead of this weekend's Singapore Grand Prix.
"I think we should do it anyway. I would rather see Ferrari with three cars, or any of the other top teams with three cars than having teams that are struggling."
Asked if more could be done to help the F1's smaller teams, Ecclestone replied: "I've been around - most people say too long - but long enough to know there are always people at the back of the grid."