Lazio and Juventus have both escaped fines from the Italian football federation despite the referee's reports from their Coppa Italia clashes noting racist remarks aimed at opposing players.
Roma defender Antonio Rudiger was the target of jeers and monkey noises during the match against Lazio on Wednesday, and an announcement was made asking fans to stop.
But the FIGC's disciplinary commission said it was "impossible to ascertain the number or percentage of the fans who joined in the chant," and declined to issue a fine.
Roma midfielder Kevin Strootman said something more should have been done.
"Yes, I heard them too," he told RAI. "It's always disgusting. Rudiger hasn't said anything, but certainly this is something the federation needs to answer to.
"We just have to do our jobs. Sadly, people do this from time to time. But I think it was just a few of them, not many."
On Tuesday, Juventus fans aimed a chant at Napoli defender Kalidou Koulibaly, but the FIGC said it was too short to deserve a fine. Koulibaly was also a target of Lazio fans in February.
However, Juventus were fined €10,000 for a brief chant for "territorial discrimination" targeting people from southern Italy.
Meanwhile, the disciplinary commission also confirmed that Lazio midfielder Marco Parolo will be suspended for the second leg against Roma after picking up a second yellow card in the cup.