The Soviet Union lost around 26 mio people in WW2, some historians are even arguing the number exceeded 30 mio. Exactly how many of these were Russians and not Ukrainians or Belarusians I can't remember, but these are only death counts.
Now we also take into consideration all those who was turned into cripples/injured so bad they would never recover. And wouldn't be surprised if that is around 10 mio+ also.
So to me it's not even a surprise if the Russians are running out of manpower. Russia's demographics never recovered post WW2. Too many young males and men in general were killed in WW2 for them to ever truly recover. The population is skewed quite heavily in favor of the women in Russia.
With all this taken into account, no wonder they're scraping the bottom of the barrel. They been fighting a European country with a big population for the last 3 years, not just some Mujahidin in Afghanisthan. And fighting the Afghans was another big reason the Soviet Union collapsed.
Here they're fighting a conventional army and their losses are pilling up high - as expected.
@DAiDEViL
You Germans really went all out on them.