"The Wagner Group is likely moving towards a down-sizing and reconfiguration process, largely to save on staff salary expenses at a time of financial pressure," said the UK Defense Ministry.
Russian President Vladimir Putin met with Wagner mercenary chief Yevgeny Prigozhin days after the attempted coup.
"I see Prigozhin is already flying in on this plane," President Alexander Lukashenko was quoted as saying. "Yes, indeed, he is in Belarus today."
Wagner mercenary boss Yevgeny Prigozhin had demanded that Shoigu and Valery Gerasimov, the Chief of the General Staff, be handed over to him so that he could "restore justice."
Ukrainian leadership celebrates military dysfunction in Russia, but as Putin quickly quells the budding Wagner rebellion, it's unclear if Ukraine will manage to capitalize on Russia's turmoil.
Kyiv says it wants to reclaim all of its territory, including the Crimean peninsula
The ministry said this was part of a wider reward scheme under which more than 10,000 Russian servicemen had received individual bonuses.
Prigozhin has repeatedly attacked Russian President Vladimir Putin's top military brass for what he casts as treachery.
While Russia is accusing the Ukraine of blowing up its own dam, the Ukraine and other Western countries believe that Russia is responsible for Kakhovka dam's destruction.
The UK Defense Ministry recently assessed that Russian forces had been suffering from artillery shell shortages, leading to rationing and the use of old shells.