The group of 32 athletes - including six-time Olympic gold medalist Viktor Ahn, three former National Hockey League players and world biathlon champion Anton Shipulin - failed to pass mandatory IOC vetting, imposed as a result of Russian doping at the 2014 Games.
Bach says the International Olympic Committee has dealt with the issues as best they can and insists that they, CAS and the World Anti-Doping Agency (WADA) will convene to ensure there is not a repeat of the chaotic build-up to the Rio 2016 Games.
Among the athletes who have not been invited are the speed skater Viktor Ahn, six times Olympic champion; the biathlete Anton Shipulin, one of the best in the world; the long-distance skater Sergey Ustyugov, and the skater Ksenia Stolbova, Olympic runner-up by pairs in 2014.
The Games in South Korea end on February 25. They have frozen all contacts with AIBA, except the ones on the working level which are necessary to implement the respective International Olympic Committee decisions, and expect another report from the boxing body, which would need to be delivered by April 30.
CAS secretary general Matthieu Reeb said the first hearing started on Wednesday but had been adjourned to Thursday, resuming at noon, "in order to hear also the second case".
IOC President Thomas Bach said at a press conference that the joint march will be a "very emotional moment", not just for the Olympics but also for him personally as a citizen of Germany, a once-divided nation.
The IOC has formally banned Russia from Pyeongchang but has allowed 168 "clean" athletes to take part under a neutral flag and may still allow the Russian flag at the closing ceremony.
"It is sad for me to see other Russian athletes posting videos and photos from Korea".
"These athletes and many million other people, they will believe in this gesture and the athletes are going to show it", said Bach, adding he knew the feeling of division having competed as a fencer at the 1976 Summer Olympics for what was then West Germany. Their appeals against Olympic bans were fully satisfied, while the request to reexamine the cases of another 11 were only "partially upheld".
"A huge amount of work has gone in to making sure we can ensure that there can be a path for clean athletes from Russian Federation to compete in these Games here".