If Putin becomes ill, the former head of MI6 predicted that Patrushev would take his place.
One of the few people who have Putin's ear is Patrushev.
Richard Dearlove made a comment on his show.
The former head of British intelligence predicted that a former colleague of Putin's could become the next president of Russia.
There have been conflicting reports that the health of the Russian leader could be in decline. According to reports, potential successors have begun to be discussed in case Putin is forced out over the Ukrainian invasion or dies of a disease.
Sir Richard Dearlove, who served as head of the UK's Secret Intelligence Service from 1999 to 2004, said this week that the most likely heir candidate is the secretary of Russia's Security Council.
"I'm pretty sure it would be Patrushev," Dearlove said on the Thursday episode of "One Decision," which he co-hosted, during a discussion about the impact of Putin's war in Ukraine.
The former MI6 chief thinks that Putin is going to live a long time. In May of this year, Dearlove predicted that Putin would be forced into a medical facility for long-term illness in order to remove him from office without a coup.
Putin said in June that the claims about his health were overstated. "As far as we can tell, he's completely healthy," said William Burns, the director of the CIA.
Patrushev's emergence as a dependable leader and frequent promoter of Russia's war in recent months has prompted questions about his personal aims and whether or not he may be trying to get Putin's power for himself.
A Kremlin spokesman told The Washington Post that Patrushev's role had not changed, and that the security secretary had not gained new powers. The Security Council denied to the outlet that Patrushev was trying to get an advancement.
Experts think Patrushev is a man to watch. The experts on Russian money predicted on Thursday's "One Decision" episode that if Putin fell ill, it would be a member of the Siloviki, or high-ranking officials in Russian institutions, that would take his place. Patrushev is similar to the national security adviser in the US.
In the wake of the war, Russia's oligarchs have become fodder for fascination, but it is unlikely that Putin's replacement will come from such a pool, according to Shelley.
She said that the tycoons have little influence on Putin. His advisers are in a very close circle with him.
The experts said whether Patrushev or any other replacement would last is a question that needs to be answered.
Business Insider has an article on it.