The Brazilian club allegedly offered to pay €6.1 million in several installments over the next five years, a proposal which falls short of CSKA's ambitions.
"Flamengo's offer is completely inadequate," CSKA spokesperson Sergei Aksenov is quoted by AFP as saying.
"We made them clearly understand that we are not willing to let him go for less than €10m.
"This figure is clearly inferior to the player's value, but our board is willing to attend to his request, taking into account all he has done for CSKA."
Vagner Love has aired his wish to return to his homeland of Brazil after spending the last eight years of his career at the Russian capital club.
According to Globoesporte, Flamengo have scheduled a meeting with the striker on Friday to discuss personal terms.
The Brazil international enjoyed a fruitful loan spell at Flamengo in 2010, netting 23 goals in 27 appearances for the Rio de Janeiro-based club.
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