The 21-year-old Dynamo Moscow forward, who featured as a substitute in the 4-1 win over Czech Republic, suffered a hamstring tear in training on Thursday.
The Dynamo Moscow striker pulled up with a hamstring problem in training in Sulejowek on Thursday and subsequent scans have revealed a tear.
Consequently, Kokorin will play no part in Saturday's meeting with the Greeks in Warsaw and further tests are now required to determine just how long the 21-year-old will be out of action.
The versatile forward, who can also play out wide, saw six minutes of game time at the end of the opening-day rout of Czech Republic but he was an unused substitute in subsequent draw with co-host Poland.
Dick Advocaat's men need only a point against Greece to guarantee a place in the quarterfinals.