The Benfica star has been heavily linked with a move away from Estádio da Luz this summer, with the Premier League touted as his most likely destination.
In addition to Chelsea, Everton have also been credited with an interest in the Paraguay international's signature, though it's Jose Mourinho who seemed destined to lure Cardozo to Stamford Bridge.
The Blues have been on the lookout for a new striker during the current transfer window, and see the South American - who has scored 105 goals in just 160 league appearances for Benfica - as a value-for-money addition ahead of the 2013/14 campaign.
Last week, Turkish giants Fenerbahce looked set to hijack Cardozo's transfer, but after failing to reach agreement over a fee with the Portuguese club, negotiations between the two parties broke down.
Now, Spartak are ready to steal a march on rivals Chelsea, and are ready to meet Benfica's £15million valuation of the 30-year-old, in a bid to lure Cardozo to Russia.