There were 3 Russian players last year who were important in Sochi: Malkin, Ovechkin and Tarasenko. The rest of the Olympians were any one of 100 Russian forwards who could have just as well filled out the 3rd and 4th lines, which may be why Russia finished 6th at Sochi. Ovechkin played in Semis against the USA less than 24 hours after leaving the ice from a 7th game Stanley Cup elimination.
Of the Olympic defensemen, without looking it up, the only one who played last year that I remember was Belov, far from their key defenseman. On the other hand, there were 4 young and inexperienced D men who were mismatched in all 3 games that Russia lost. Of the games Russia lost, Canada was not demonstrably better than the USA or Finland, but they did score more goals by sheer luck and an uncharacteristically awful goaltending performance by Bobrovsky. That game is not a really good view of the differences between the 2 teams (Russia loses the SOG war even when it wins the game).
