Iranian champions Sepahan won the clash in Isfahan 1-0, but Al Sadd are understood to have asked to have the result handed to them 3-0.
Goal.com understands Al Sadd believe Sepahan goalkeeper Rahman Ahmadi was ineligible for the game after receiving two bookings earlier in the ACL.
Ahmadi joined Sepahan recently from Persepolis, whom he played with earlier in the ACL.
The Iranian goalkeeper received bookings against Al Ittihad and Al Wahda in the group stage whilst with Persepolis.
However, Ahmadi did not play in Sepahan's Round of 16 clash with Bunyodkor.
Both clubs will wait on the ruling of the AFC's disciplinary committee.
Only two months ago, Iran's Olympic team made a similar mistake when they fielded Kamal Kamyabinia, who was an ineligible player after two previous bookings, in their second round qualifier against Iraq.
Iran won the match 1-0 in Iraq, but later had the result overturned to a 3-0 defeat, eventually seeing the team bow out of the qualifiers.