Television cameras caught a Chelsea fan allegedly aiming racist abuse at Sterling during the Blues' 2-0 win over City at Stamford Bridge on Saturday.
Chelsea and the British police are investigating the incident. The club have suspended four fans until they have concluded their probe, with the threat of permanent bans if they find evidence of racist behaviour.
Loftus-Cheek and Sterling were part of England's squad that reached the semi-finals of the World Cup in July.
"I haven't spoken to Raheem about it. I prefer to leave him and let him deal with it mentally himself," said Loftus-Cheek on Wednesday ahead of Chelsea's Europa League tie in Hungary against Vidi.
"He's a strong-minded person so I'm sure he will be alright but I think he was right to say what he said.
"I don't think it should be in the game, or anywhere, so him speaking out was the right thing to do and if it happened to me I would do the same."
Loftus-Cheek said he had never personally suffered racism in football, although he had off the field as a child, but believes progress is being made.
"I'm not surprised to be asked about it because I'm a black player. People want to know my opinion about it and I'll give my opinion about it.
"It's something that’s not nice for us black players but we've definitely made some steps if we're looking back.
"It's a negative point if it is racial abuse, but on a positive point we have made some steps."
Chelsea manager Maurizio Sarri said the club will do all it can to cut out racial discrimination of any kind.
"First of all I want to say I condemn any form of discrimination," said the Italian.
"I think I have to stop here because there is an investigation, and so I think it's better not to say anything more. But of course my opinion is that I condemn every sort of discrimination."