By ESPNSTAR.com staff
The holding midfielder has one year left on his contract with the current La Liga champions.
And Diarra now appears on the verge of joining former Valencia coach Unai Emery in the Russian capital despite interest from AC Milan.
"I think it will be hard to see him move to Italy," Claudio Vigorelli told Sportitalia.
"First of all, because he has one more year left on his contract with Madrid.
"And then because he has a good offer from Spartak Moscow."
Spartak coach Emery is on the lookout for reinforcements in midfield ahead of the new season with the 27-year-old Diarra seen as the ideal addition to his squad.
Diarra joined Madrid from Portsmouth in January 2009.