"It's important to underline and highlight that Keita Balde's test result is negative, so clearly no banned substances have been found in his test," a statement from Balde's agents Sports Management said.
"However, in accordance with the disciplinary code, any doping-related sanction imposed by another national or international sports association, or national anti-doping organisation, is automatically accepted by Fifa and must be recognised by all confederations and associations.
"As a ... consequence, the sanction applied by the Italian Anti-Doping Organisation is subject to recognition by the Russian Football Federation."
Balde, formerly with Inter, Lazio and Sampdoria in Italy, joined Spartak in August and had been named in the Teranga Lions' 29-man squad for forthcoming friendlies against Bolivia in Orleans on Saturday and Iran in Austria on Tuesday 27 September.
Meanwhile, Noah Fadiga has also been forced to withdraw from the Senegal squad after suffering a concussion while playing for club side Brest.
Born in Girona, Spain, to Senegalese parents, Balde came through the prestigious youth ranks at Barcelona from the age of nine until 16 when he signed for Italian side Lazio in 2011.
He scored 41 goals in 185 Serie A appearances, in a career that has taken him from Italy to Russia via spells in Italy and with French side Monaco.
Eligible for his country of birth, he opted for Senegal in 2015 and made his debut as a substitute against Niger in March 2016.
In Qatar, Senegal will play the Netherlands in their opening game before facing the hosts themselves and Ecuador in Group A.