On both occasions, Medvedev criticized the government for not doing enough to help industry and business cope with the global financial crisis, which has hit Russia hard.
"The planned measures are being fulfilled slower than we counted on and, most important, slower than the current situation demands," Medvedev said during a visit Sunday to an engine plant outside Moscow with government ministers.
Two weeks earlier, Medvedev characterized the government's anti-crisis program as "well-balanced but not ideal."
But political analysts played down the idea of a rift, saying the remarks are more a sign of the growing economic pressures. Putin remains the far more powerful figure and Medvedev is too weak to challenge him even if he wanted to, analysts said.
"A revolt by Medvedev is impossible," said Olga Kryshtanovskaya, a sociologist who studies the Russian political elite. Medvedev's televised criticism of Putin's government was meant only to reassure the population that more would be done to relieve their economic pain, she said.