Alex, can you explain why Chuzhanova/Mintsev competed at Russian cup in seniors? It doesn't make sense! They need to qualify for nationals. They have no chance to qualify for nationals in seniors (I will explain below why not) but they would have a chance to qualify to junior nationals, if they compete at two Russian cups in juniors.
To qualify for nationals in juniors, the skaters need to either compete at JGP, or qualify based on their results at the Russian cup events (in juniors).
There is 12 spots in pairs at the nationals, and this season there was seven pairs competing at JGP, so there is five spots open for junior pairs to qualify through Russian cups. Chuzhanova/Mintsev did not get JGP event this season so they need to compete at two junior events. (as far as I am aware, senior events don't count for qualification for junior nationals). This was Russian cup number three, so they have only two more Russian cups left. If one of them is ill or injured at the time the remaining two Russian cups are on, they would be out of nationals. Wouldn't it make more sense compete now in juniors and leave the senior one as the last one, after they had their qualifying events? (They have done one event, but they still need one more to do).
The reason why they have no chance to get to seniors nationals:
There is 12 spots at pair seniors nationals.
Those who are competing at GP will get spot at nationals automatically. (7 pairs have GP event, that's seven spots gone)
Those who qualified to JGPF have right to compete at senior nationals if they wish to. (not compulsory) - that's another 4 spots possibly gone.
It seems that all the remaining senior pairs will be fighting at Russian Cup events for the one last spot. At the moment my bets are on Alisa Efimova/Alexandr Korovin who placed first in one of their events and now are currently at first place after the SP at their second event.
There may be some unexpected openings for spots at senior nationals, such as illness or injury of anyone from those who qualified, or one of those four pairs who qualified through JGPF may decide not to compete at senior nationals and concentrate on their junior nationals that take place a month later, or there is a chance that one of the seniors (maybe Volosozhar/Trankov) will get excused from nationals (and will be nominated to compete at Europeans even without having to compete at the nationals, based on their results from GP events) but as it is now, it seems that it is nearly decided who is competing at seniors nationals. So why would Chuzhanova/Mintsev do senior event before they even qualified for junior nationals?