Fenerbahce's team bus was attacked with gun fire as the team left a rival stadium following a match.
The coach driver was taken to hospital after sustaining injuries in the incident, which happened as the team were travelling from the city of Rize to the airport in the neighbouring city of Trabzon, to return to Istanbul.
No players were injured.
Champions Fenerbahce had just beaten Black Sea side Caykur Rizespor 5-1 in Turkey’s Super Lig.
The club's general secretary, Mahmut Uslu, described the incident as "very wrong".
"We come here to do sport, we come to play football," Uslu said.
The club posted pictures of the bus on their website, showing a smashed window and damaged windscreen. The pictures also appeared to show blood on the driver’s seat and the steering wheel.
"The latest situation is that it appears to be a gun," governor of Tabzon Abdulcelil Oz said. "It is too soon to say anything definite, but it appears to be a type of bullet fired by a rifle."