I have no idea how many "followers" Nadalny has, also i do not know whether he was the head of the 65,000 protesters in the march demonstration 2017, when a thousand or so were arrested. I am also not sure whether his nationalist leaning would be good for Russia, or if he just does that to amass more people against Putin or "the corruption".
I do not see any other independent candidate. Medvedvev? Lol. I just saw a video where Medvedvev and Putin were practicing in a gym, before having breakfast together.
https://www.politico.com/news/2020/0...navalny-400063