The new 2021 Formula One calendar still has a gap, but 
Auto, Motor und Sport have reported that this will be filled by 
Portimao. However, some races are still in the pipeline.
The new 2021 
Formula 1 calendar was announced on Tuesday morning with some adjustments. The 
Australian Grand Prix has been moved to November, the 
Bahrain Grand Prix is now the first race of the F1 season and 
Imola returns to the calendar. However, this is not the end of the changes.
Portimao a certainty
Indeed, there is still an open spot that has yet to be announced (TBC). 
Portimao seems to be the most likely candidate to fill this spot and 
Auto, Motor und Sport have reaffirmed this. According to the German source, this race will be announced as the second European race at a later date.
However, there are also some races in the pipeline. According to AMuS, Monaco has until mid-May to determine whether the race can go ahead. Just like in Australia, Monaco has a problem to arrange everything in the time because of the coronavirus and also the races in Baku and Canada are in doubt if they can take place under the current circumstances.