The 49-year-old said that starting places against Roma will be up for grabs at the Sukru Saracoglu Stadium, where they will be aiming to secure an advantage in their Europa League quarter-final tie.
"From Friday we will think about the Rome Derby, but not before," Football Italia quotes Petkovic as saying.
"All the players in the squad can feature, then I must decide if they start or are on the bench.
"We have to make the most of our physical and psychological characteristics to beat Fenerbahce. We are here to dominate our opponents."
The Biancocelesti will play next Thursday's second leg behind closed doors.