"It could lead to a heavy ban. I hope nothing happens, but it's difficult," Inter president Massimo Moratti said.
The Italian Football Federation has requested TV evidence of the incident and the BBC African Footballer of the Year nominee could be banned for between two to four games.
An Eto'o ban would be a huge blow for Inter coach Rafael Benitez who has had to cope with injuries to key players including Diego Milito.
Inter have also suffered a loss of form and currently lie in sixth place in Serie A, nine points behind their cross-city rivals, AC Milan. Eto'o has scored 17 goals in all competitions this season. The Italian league has used video evidence to ban Fiorentina striker Alberto Gilardino for two games after he scored a goal with his hand.
Inter host Dutch side FC Twente in the European Champions League on Wednesday.