Russian President Vladimir Putin’s latest reshuffle of the top brass in charge of Ukraine operations reveals a deeper power struggle between Moscow’s military command and its domestic detractors, analysts say.

One of the most prominent and powerful critics of Moscow’s strategy in Ukraine is Yevgeny Prigozhin, the leader of the Wagner Group — a private military company fighting in Ukraine. Prigozhin has slammed defense chiefs for a series of humiliating losses and retreats during the war.

His criticism seemed to bear fruit with the October appointment of Gen. Sergei Surovikin as the overall battlefield commander for Russian troops in Ukraine. Prigozhin praised the designation and described Surovikin — nicknamed “General Armageddon — as “the most able commander in the Russian army.”

Surovikin later oversaw a massive aerial bombardment of Ukraine, damaging a large proportion of its energy infrastructure at the onset of winter. He also had the unenviable task of suggesting (in what appeared to be a choreographed meeting on Russian television) to Defense Minister Sergei Shoigu that Russian troops should withdraw from a part of Kherson in southern Ukraine in November — an unpopular move that was nevertheless endorsed by Prigozhin.

Surovikin’s mandate has ended just three months later. With few territorial gains to show in Ukraine, he was on Wednesday replaced with commander Gen. Valery Gerasimov and appointed as his deputy, the Russian defense ministry said. Gerasimov is a Putin loyalist and was the highest ranking uniformed officer in Russia in his previous role as chief of Russia’s armed forces.

Analysts say the replacement could point to Moscow’s shifting sentiment toward Prigozhin and the Wagner Group, on top of Putin’s dissatisfaction with the lack of tactical advances in the Moscow-styled “special military operation” in Ukraine.

Long-term Putin associate and ally Prigozhin has become more outspoken during the war jas his estimated 50,000-men strong private military company — which also recruits from Russian prisons — has achieved successes on the battlefield. Nonetheless, Prigozhin’s criticism of Russia’s military commanders and frequent boasts over the Wagner Group’s triumphs have raised heckles in Moscow.

On Tuesday, Prigozhin claimed that his military company had single-handedly taken control of Soledar in Donetsk, a key target and the site of intense clashes for months. The Kremlin was far more cautious about declaring a victory, however, and Russia’s Ministry of Defense said its elite airborne forces had surrounded Soledar from the north and south while fighting continued in the town center.

Analysts at the Institute for the Study of War said Gerasimov’s promotion,and the broader command overhaul likely sought to reinforce “traditional power structures” like Russia’s Ministry of Defense (MoD) against challenges from Prigozhin and other “siloviki” — or “strongmen” — who have been critical of Moscow’s Ukraine military strategy.

“Gerasimov’s appointment as theater commander likely advances two Kremlin efforts: an attempt to improve Russian command and control for a decisive military effort in 2023, and a political move to strengthen the Russian MoD against challenges from the Russian millbloggers and siloviki, such as Wagner Group financier Yevgeny Prigozhin, who have criticized the Kremlin’s conduct of the war,” analysts at the ISW said in an assessment Wednesday evening.

“The elevation of Gerasimov and the Russian MoD over Surovikin, a favorite of Prigozhin and the siloviki faction, is additionally highly likely to have been in part a political decision to reassert the primacy of the Russian MoD in an internal Russian power struggle,” they added. Gerasimov’s promotion could also be “a signal for Prigozhin and other actors to reduce their criticism of the MoD.”

“Prigozhin has relentlessly promoted the Wagner Group at the expense of the Russian MoD’s reputation and may double down on his flashy advertisements on Russian social media and state-affiliated outlets to assert the superiority of his forces,” the ISW concluded.

The U.K.’s Ministry of Defence also commented on the reshuffle Wednesday, calling it an indication “of the increasing seriousness of the situation Russia is facing, and a clear acknowledgement that the campaign is falling short of Russia’s strategic goals.”

It added that the move was likely to be greeted with “extreme displeasure” by much of the Russian ultra-nationalist and military blogger community, “who have increasingly blamed Gerasimov for the poor execution of the war.”

“In contrast, Surovikin has been widely praised by this community for his championing of a more realistic approach. As a now deputy commander, his authority and influence is almost certainly hugely reduced.”

Surovikin may benefit from not being in command, according to political scientist Mark Galeotti, who said Gerasimov was being handed “the most poisoned of chalices.”

“For Gerasimov …it is a kind of demotion, or at least the most poisoned of chalices. It’s now on him, and I suspect Putin has unrealistic expectations again,” Galeotti, director of the consultancy Mayak Intelligence, said on Twitter Wednesday.

“It has been pretty clear that there will be spring offensives …There may well be some advances, but nothing decisive (and the Ukrainians themselves will be looking to a spring offensive). In many ways, I don’t think Moscow’s strategy hinges anyway on battlefield victory — it’s more about politics. In other words, demonstrating to the West that Russia is in this for the long haul, and hoping that we will lose the will and unity to continue to support Kyiv,” he said.