Oscar was handed a yellow card after going to ground against Southampton on Wednesday, while Ramires was accused of simulation after winning a penalty against West Brom in November
Oscar was cautioned for diving in Wednesday's 3-0 win at Southampton as he tried to buy a penalty from Kelvin Davis, while Ramires was accused of going to ground easily against West Brom in November.
While Mourinho agrees with the Oscar decision, he insists it was a one-off mistake from the 22-year-old, and is a firm believer that none of his players can be classed as a cheat.
"It's impossible for [Oscar] to get a reputation, unless somebody wants to be unfair and to clean the image of other people by using Oscar's situation in the last game," the Portuguese told reporters.
"I want to make it clear. There are many divers in the world of football. There are many divers in some big clubs in the world of football.
"There are some divers in England. Not many, some. In Chelsea, no divers, no divers at all.
"Oscar made a mistake, which he tells me and I believe him, he was completely convinced the goalkeeper was coming to smash him.
"The goalkeeper didn't, he made his mistake, he was punished with a yellow card, he accepted the yellow card in a very calm way.
"His manager comes after in the press to say 'well done Mr Atkinson'. End of story. Here we don't have divers."